The Weather Guard 121-52-03 is the previous-generation full-size low-profile aluminum saddle box, offered here as the proven, value-priced version that came before the current 1Key UltraLock update. Security comes from the One Key push-button high-security lock, which codes multiple boxes on a truck or a whole fleet to one key and stays PowerSync capable for Weather Guard interior lights and remote keyless entry add-ons. The five-piece welded aluminum diamond-plate body wears a textured matte black ARMOR TUF finish that kills glare and hides fingerprints, dust and light scratches for a clean, understated truck. Its low-profile lid line sits lower across the bed for better rear visibility while still delivering 10.2ft³ of weather-sealed storage over the top bed rails behind the cab. A reinforced lid on gas struts and a full-perimeter D-shaped weather seal keep rain and grit out load after load.
What's Included:
121 Series full-size low-profile aluminum crossover (saddle) tool box in matte black
One Key push-button high-security lock, keyed alike
Under-rail mounting clamps and hardware for a no-drill install
Welded Aluminum Diamond-Plate Build A five-piece welded aluminum diamond-plate body with a reinforced C-channel front panel keeps this box strong yet light. It resists jobsite abuse and road salt without adding the weight of a steel box. This one is finished in textured matte black ARMOR TUF powder coat.
Textured Matte Black ARMOR TUF Finish Textured matte black ARMOR TUF powder coat throws off almost no glare and swallows fingerprints, dust and small scuffs that a glossy coat would show. It gives the box a tactical, understated look and wipes down fast between jobs.
One Key Push-Button High-Security Lock This redesigned saddle box uses a push-button high-security lock that codes multiple boxes on a truck or fleet to one key, and it is PowerSync capable for Weather Guard interior lights and remote keyless entry accessories.
Full-Perimeter Weather Seal A memory-resistant D-shaped, multi-ridge weather strip runs the entire lid perimeter to keep rain, dust and debris off your tools, so your gear stays dry and ready in any weather.
Reinforced Lid With Gas Struts Gas struts hold the reinforced lid open near 90 degrees for easy one-handed access, and welded strut shields protect them from damage. The steel-reinforced lid resists flex and stands up to daily use.
Saddle Fit Across The Bed By straddling the two bed rails behind the cab, the box leaves the bed floor wide open for plywood, ladders and long cargo. Enhanced tie-down buckles anchor loose loads and a 12V PowerSync-ready port supports interior lighting and electrical upfits.
Fit guidance: Crossover, or saddle, boxes mount across the truck bed on top of the two bed rails just behind the cab, so the box straddles the bed and leaves the bed floor open. At about 72" wide this size fits standard-width full-size pickups, and because it sits on the rails rather than the bed floor it works with short, standard and long beds on those trucks. Always measure your bed rail width and check clearance behind the cab before ordering. It is not designed for compact or mid-size trucks.
Mounting: Under-rail clamps and hardware included, no drilling required
Electrical: 12V PowerSync compatible access
Weight: About 79 lb (shipping weight)
Warranty: Limited Lifetime
Made In: USA
Installation
Type: Saddle mount across the top bed rails, clamp-in with no drilling · Time: About 20 to 30 minutes · Tools: Socket or wrench set and a tape measure; no drill needed with the included under-rail clamps · Difficulty: Easy, best done with two people for the lift
Set the box across the two bed rails behind the cab and center it left to right. Hook the included clamps under each bed rail and tighten the hardware evenly so the box sits flat and the lid seals all the way around. Because the box is wide, have a second person help lift and hold it while you clamp it down. Follow the Weather Guard installation instructions for exact clamp placement and torque.
Watch the installation walkthrough:
Resources
Everything you need for your Weather Guard 121 Aluminum Crossover Truck Tool Box, Full-Size Low-Profile, Matte Black, in one place.
Warranty. Limited Lifetime Warranty from Weather Guard against defects in materials and workmanship.
Freight shipping. This item is oversized, so it ships by freight to the lower 48 states and typically arrives in 3 to 7 business days. The freight cost is shown at checkout before you pay.
Inspect on delivery. Please inspect the packaging before signing. If you see any damage, note it on the delivery receipt and contact us right away, and we will make it right.
Returns. Unused items in their original packaging can be returned within 30 days of delivery. If an item arrives damaged, defective or wrong, return shipping is on us. See our Returns & Refunds Policy, or email support@prestigetruck.com with any question.
About Weather Guard
Weather Guard has built professional-grade truck and van storage in the USA for decades and is the storage brand tradespeople, contractors, and fleets reach for first. Its steel and aluminum tool boxes, ladder racks, and van-interior systems are engineered to survive daily jobsite abuse and keep expensive tools secure and organized.
Known for weather-tight seals, patented locking systems, and heavy-gauge construction, Weather Guard products mount cleanly on work trucks and vans and stand up to years of hard use. The lineup spans crossover, low-side, and saddle truck boxes, ladder and van racks, drawer units, and fuel and utility tanks, so an entire work vehicle can be outfitted from one brand.
Backed by a strong manufacturer warranty and US-based support, Weather Guard is the name pros trust to protect the tools their livelihood depends on.
Authorized Weather Guard dealer. Prestige Truck is an authorized dealer of Weather Guard, so every tool box, rack and storage product you buy is 100% genuine and factory-new, covered by the full Weather Guard manufacturer warranty, and backed by our own US-based support team.
Weather Guard's official hardware video zooms in on the clamp and bolt kit that secures its truck boxes to the bed rails without drilling. It is a helpful close-up companion to the full box install and shows how the mounting brackets hook under the rail lip and tighten down. Use it alongside the printed instructions that ship with the box.
Weather Guard Truck Box Lineup and 1Key UltraLock
This official Weather Guard overview tours the current truck box lineup and the 1Key UltraLock security system that runs across it. You see how one coded key can open every Weather Guard box on the truck, from saddle to lo-side to hi-side, with a pop-up red button that tells you at a glance whether a box is locked. It highlights the sloped, reinforced lids and the ARMOR TUF powder coat that let these boxes shrug off weather and jobsite abuse. If you run more than one box, or a whole fleet, it shows why keying everything alike saves time every day.
How to Replace the Lid on a Saddle Truck Box
Weather Guard's step-by-step guide to taking the lid off a saddle truck box and fitting a replacement. It covers the hinge and strut hardware that carries the lid, which is the part that takes the abuse on a box that gets opened twenty times a day.
Keep it bookmarked rather than watching it now. It is the reference you want the day a lid gets damaged on the job, and it comes straight from the manufacturer so the hardware and the sequence are correct.
Weather Guard's official hardware video zooms in on the clamp and bolt kit that secures its truck boxes to the bed rails without drilling. It is a helpful close-up companion to the full box install and shows how the mounting brackets hook under the rail lip and tighten down. Use it alongside the printed instructions that ship with the box.
Weather Guard Truck Box Lineup and 1Key UltraLock
This official Weather Guard overview tours the current truck box lineup and the 1Key UltraLock security system that runs across it. You see how one coded key can open every Weather Guard box on the truck, from saddle to lo-side to hi-side, with a pop-up red button that tells you at a glance whether a box is locked. It highlights the sloped, reinforced lids and the ARMOR TUF powder coat that let these boxes shrug off weather and jobsite abuse. If you run more than one box, or a whole fleet, it shows why keying everything alike saves time every day.
How to Replace the Lid on a Saddle Truck Box
Weather Guard's step-by-step guide to taking the lid off a saddle truck box and fitting a replacement. It covers the hinge and strut hardware that carries the lid, which is the part that takes the abuse on a box that gets opened twenty times a day.
Keep it bookmarked rather than watching it now. It is the reference you want the day a lid gets damaged on the job, and it comes straight from the manufacturer so the hardware and the sequence are correct.
Frequently Asked Questions
Straight answers on specs, fit and support
Will the 121-52-03 fit my truck?
It is a full-size low-profile crossover, or saddle, box that mounts across the top bed rails behind the cab, so it fits full-size pickups such as the F-150, Silverado and Sierra 1500 through 3500, Ram 1500 through 3500, Tundra and Titan. It needs about 72" of rail-to-rail width. Measure your bed rails and check clearance behind the cab first, and note it is not designed for compact or mid-size trucks.
Does it require drilling to install?
No. The box ships with under-rail clamps and hardware, so it mounts without drilling into your truck. Most installs take about 20 to 30 minutes and go easiest with two people to lift and hold the box while you clamp it down.
How does the lock on this saddle box work?
This earlier-generation saddle box uses a One Key push-button high-security lock. Press the button to release the lid, and the keyed cylinder lets you code several boxes on one truck, or an entire fleet, to a single key. It is PowerSync capable as well, so it pairs with Weather Guard interior lights and remote keyless entry accessories.
Will the matte black finish fade or stain in the weather?
No. The textured matte black ARMOR TUF coat is built to shrug off UV fading and corrosion, and the full-perimeter D-shaped seal keeps rain and dust off the contents. Its flat, low-sheen texture also does a good job hiding water spots and road film between washes.
Is this an earlier-generation box, and why does it cost less than the current model?
Yes. This is the previous-generation 121 low-profile saddle box, built around the proven One Key push-button high-security lock and PowerSync wiring instead of the newer 1Key UltraLock hardware on the current version. The welded aluminum diamond-plate body, low-profile lid line, weather seal and no-drill mounting are the same design, so you get the same day-to-day performance at a value price.
What is it made of and how big is it?
This previous-generation low-profile box is five-piece welded aluminum diamond plate under a textured matte black ARMOR TUF coat. It measures 72"L x 20"W x 18"H, holds 10.2ft³, and ships at about 79.05 lb, so it is light, low and value priced.
What our customers say
4.8 · 144 reviews
5★1174★243★22★11★0
Photos from owners
+4
chas24
Verified
08/12/2026
Truck box
Truck box. Is great. Just had a little issue with it not opening from one side because the rod that worked the latch was too short. I fixed it myself and it works great now
JRK1997
Verified
06/20/2026
Weather Guard Tool Box
This is the best toolbox I have ever owned nice and very sturdy. I also love that it is low profile and the locks and keys are second to none. This has sold me from now on I will only be buying Weather Guard toolboxes for life!
HomeDepotCustomer
Verified
06/01/2026
This tool box was easy to install....
This tool box was easy to install.
Tommy Herdman
Verified
04/23/2026
Happy with my truck bed tool box
Very light, sturdy, and a low profile. It’s great for the job site…and it looks great on my truck. It’s top of the line for bed tool boxes, with ease of installation, locking and unlocking is a snap, with lots of room for tools, lubricants, and hold down straps.
JEFF T
05/28/2026
There's a reason I buy Weather Guard
This is my third Weather Guard toolbox and I can say without a doubt they just keep getting better and better. The construction, the finish, and the locks are the best yet. But the real reason I buy Weather Guard is the phenomenal service I count on and received from Susan in customer care. I called last Thursday with a concern about the anchor points and label on my box, and today (Tuesday) I came home to this package waiting for me just as promised. She was knowledgeable, professional, pleasant and resolved my concern completely and quickly. There's a reason I buy Weather Guard - and her name is Susan. Thank you.
Cksl
Verified
08/29/2025
Awesome
Great tool box. I like the low profile design and matte finish!
King
Verified
07/27/2025
Excellent quality. Easy pickup. Only regret is I should have...
Excellent quality. Easy pickup. Only regret is I should have got the bigger box. Mines already full tools.
Angel15
Verified
05/24/2025
Tool box is great. Only thing is the mate is...
Tool box is great. Only thing is the mate is not so mate . Previously had a mate box and weather guard looked like a gloss next to it but other than that tool box still looks great and im really satified with the purchase
RonM
06/23/2025
Initial Review
Product arrived damage free. Finishes were as expected. The install could be better due to the tie down thread difficulty. The include tray has 4 slots for dividers, only 3 dividers included. Tray has pads on it that facilitate it sliding back & forth while driving which is annoying & damaging.
Joe
Verified
05/08/2025
Really easy to mount and a nice heavy duty box...
Really easy to mount and a nice heavy duty box
Anonymous
07/14/2026
Matt Black Toolbox
My husband absolutely loves it. He loves the way it appears, locks, is sturdy, and extremely well built.
HomeDepotCustomer
Verified
04/03/2025
The box showed up quickly and not damaged. Very happy with the transaction as a whole. The box is expensive but is a much better quality than others.
Alan
Verified
02/08/2025
good toolbox...
good toolbox
Fred
Verified
01/04/2025
Bought a new truck. Researched boxes and decided to go with Weather Guard. It is a strong,
Bought a new truck. Researched boxes and decided to go with Weather Guard. It is a strong, well built box with good locks. I'm glad I went with this product.
HomeDepotCustomer
Verified
01/01/2025
Not to big not to small its perfect!...
Not to big not to small its perfect!
Dhoff
12/16/2025
Great tool box
I have owned 6 weather gaurd boxes over the years, the quality is always great. Sure they are expensive but you get what you pay for. Everything else is a cheap toy that constantly has issues. I don’t get paid to screw with my tool box all day. Pay the money and it hurts for a day, get a cheap toy and pay every day!
Bole
Verified
12/15/2024
Sharp look
Outstanding product. Quick delivery. Easy to install
Ihook716
10/01/2025
Doesn’t latch
I recently bought this low profile box. I opted to spend the extra money and get the best quality box. Unfortunately I can’t get it to close and latch properly unless I get in the bed and put all my weight on it. I have yet to find a way to adjust this. It also came with a small dent on the front face. Please help
Chevy guy
Verified
12/07/2024
Nice Toolbox
Toolbox is well built. Looks good on my silver Silverado and blends with the black bed liner.
HomeDepotCustomer
Verified
11/02/2024
This box is more durable and seals better than the...
This box is more durable and seals better than the last box I purchased. i really like the way it opensand how it is secured to the truck bed.
Michael
Verified
10/06/2024
Quality Toolbox
quality toolbox
sirvegatx
12/22/2024
Perfect Fit! Looks Amazing! Everything Just Works!
Cardboard box was damaged a bit on delivery, but toolbox was perfect with 0 scratches or dents (from MN to TX). Instructions self explanatory and installed in minutes. Lid closes securely and easily and love the look of the matte black!!!!! Fits shortbed Chevy PEFECTLY!!!
Richard Fazzini
Verified
07/30/2024
You get what you pay for...
This tool box is amazing... worth every penny full price. And even better with the ten percent off online ordering.
HomeDepotCustomer
Verified
06/12/2024
Perfect fit for my needs.
Justin
Verified
05/12/2024
Cheaper here than other stores for same product
Best tool box to protect your tools
HomeDepotCustomer
Verified
04/16/2024
Love the toolbox but in shipping I received it with a dent in it. Packaging could be better
Aaron J
04/09/2026
Changed locking mechanism
I bought this box today, I hope it lasts as long as my last one. I bought a dual lid in 2011 and has been awesome, the locking mechanism was what drew me to the product. I'm highly disappointed that Weather Guard changed there lock system. I really hopeful that the new system performs as a deterant like the old system.
John
Verified
03/01/2024
Worth the money
High quality product Very well made
HomeDepotCustomer
Verified
02/07/2024
Great product. Looks Great too. Installation was easy and took about 5 minutes.
Kevin57
11/13/2024
Poor quality for the price paid
I bought this toolbox 2 weeks ago. Have opened and closed the box maybe a dozen times. The sheet metal screws holding the latch on the lid all came loose and fell off! I would think for the amount I paid for this product , I would expect a higher level of quality. This is not the first weatherguard I have owned and have always been very satisfied with the quality. It’s sad I had to repair this box after only owning it for 2 weeks. I will add photos of my repairs . I feel this should have been done from the manufacturer, or something more than sheet metal screws.
katejay
Verified
02/03/2025
This was a great tool box, but was difficult to get installed into my 2019 Chevy truck. Th
This was a great tool box, but was difficult to get installed into my 2019 Chevy truck. The lid is not wanting to latch once installed in the truck. We followed the guidelines to the T.
JAP1
Verified
07/02/2024
Works perfect with only one issue
This is a great toolbox, only issue is make sure the key holes have a piece of black tape over them. People will sometimes mess with the keys which then “codes” them. Once that happens, you have to call weather guard to get a new lock.
Work every day
02/11/2026
It works
Good box not great if you’re looking for old school weather guard this isn’t it but works well just miss old style and quality
HomeDepotCustomer
Verified
07/10/2025
Perfect tool box and great size for my truck
Perfect tool box and great size for my truck
C Booher
Verified
08/28/2026
Awesome!!!
Love this toolbox, compliments on it everywhere i go
Rzr
Verified
06/09/2025
Easy to install. Fits and looks great. Built strong enough to keep everything secure. Ship
Easy to install. Fits and looks great. Built strong enough to keep everything secure. Shipping was fast and no damage.
HomeDepotCustomer
Verified
11/10/2024
Easy to install and top-quality manufacturing, Thicker gauge metal is superior to other br
Easy to install and top-quality manufacturing, Thicker gauge metal is superior to other brands I looked at. I considered lower quality brand to save money and so glad that I chose Weather Guard brand! It operates perfectly and we have had 4 major rain/wind storms and not a sign of moisture/dust on the interior. Locks on both sides and can unlock with just using one side, nice feature. Shipped to store and was in perfect condition, Excellent protection and palletized perfectly to avoid damages.
Anonymous
08/13/2025
Weather Guard
Worth the extra money compared to cheaper truck boxes!!
Nate
Verified
08/22/2026
Way better than by backseat floor board!
Convenient storage
Garrett
Verified
08/20/2026
Waited a long time...
I have waited years before buying a quality toolbox. Difference is amazing, wish I would have spent the money a long time ago. Ended up buying two so I could have one in both work trucks.
Clrcut
Verified
08/19/2026
Best box ever
Well built box. Excellent fit
Jman
Verified
08/16/2026
Tool box
Love this tool box. Very well built
WAYNE
04/23/2026
Excellent box, well worth the price!...
Excellent box, well worth the price!
B fuller
Verified
08/04/2026
Weatherguard
Fits well on 2500 ram truck
RW fisher
Verified
07/31/2026
Sharp toolbox , heavy duty / with nice features
Great toolbox with nice space
Water Tech
Verified
07/30/2026
Excellent
Sturdy, closes tight and locks easily. This is the best box and worth every penny.
Jason
Verified
07/19/2026
Perfect
Perfect fit. Perfect space. Super easy to install. Very happy.
Dko3030
03/05/2026
Quality control, new locks, Huge key...
The first box i got was hot garbage. Horrible welds, not square at all, lid not centered terrible. I returned and got another and its fine. I'm not a fan of the new locks, they dont stay recessed when they are locked like they used to. Wish i had locks the old style locks and the new key is huge. It is by far the largest key on my ring.
Joel
06/10/2024
Damaged
Product came damaged, otherwise no issues. Not a fan of the new locks. Feel cheap
DANMAN
05/31/2026
Low pro saddle box
Had high hopes for this box and while it isn't terrible, not quite what I expected. For the price point I was expecting a box built like a tank, and this one isn't. Saw other reviewers talk about the welds and, the welds on my box are decent but not spectactular. The lid on the box is different than most, not simetrical, kind of a weird gap in the back, not astheticaly pleasing. Have to set the locks with the key on first use which was unusual. Locks seems to be okay, not the smoothest operating. Release button on driver side seems to be a little glitchy, sometimes works good and other times hesitates, passenger side works fine. The keys are HUGE also, as long as the key fob for my ram and just about as wide. Don't really see the need for the key to be that large when it only inserts in the lock about 1". Thought the box was supposed to have the easy close feature but mine still has to…
steve
09/12/2025
Great tool box
I chose this Weatherguard tool box for the low profile and storage, it is weather tight and great, knocked off a star because the stickers were all of center on the box
Rob
12/16/2024
Weather guard truck box
Solid box with excellent latches and locks. Struts are strong. Always have problems with other top box struts getting weak. I will see if these hold up, but if they don’t, lifetime warranty! One thing i don’t like, the box lid is difficult to get patched. I have to close the lid and then push with a fair amount of pressure to get it to latch and then the other side doesn’t completely latch. Hoping the seal will lighten up over time.
RANDY
08/06/2024
Mounting
The tool box is excellent in quality and craftsmanship. It is just what I wanted. The issue that I had was with the mounting hardware though. The clips did not adequately fit the bed on my GMC
Aaron
Verified
08/21/2026
Good product
Good product. Door feels a little loose when opened all the way. Solid box
WILL
Verified
06/24/2026
Updated toolbox from a TSC brand, to accommodate use of a tonneau cover made for truck toolboxes on a 2017 F350 SRW LB. So far, great quality and space. Ordered/delivered to store for pick up - packaging was intact (no dents). Read reviews ahead, and have some thoughts of the provided steel, sliding tray. Does not fit snug, but very loose. If Weatherguard provided a rugged plastic tray - would be a much better accessory.