Blacked-out and built to work, the Weather Guard 121-5-04 wears a deep gloss black ARMOR TUF powder coat that matches modern dark trim and wheels. The wet-look shine wipes clean easily and stands up to sun, salt and jobsite abuse. Pair it with black wheels and dark trim for a clean, factory-blacked-out build that still shrugs off the weather. The deep, even shine photographs well too, which is a plus if you show or resell the truck. This full-size, low-profile aluminum saddle box straddles the top bed rails behind the cab and keeps a lower lid line for better rear visibility, with 11.0ft³ of secured, weather-sealed storage. A five-piece welded aluminum diamond-plate body with a reinforced C-channel front keeps it strong yet light, and a full-perimeter D-shaped weather seal locks out rain and dust.
What's Included:
121 Series full-size low-profile aluminum crossover (saddle) tool box in gloss black
1Key UltraLock push-button locks, 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 gloss black ARMOR TUF powder coat.
Gloss Black ARMOR TUF Finish A deep gloss black ARMOR TUF powder coat gives the box a sleek, wet-look shine that pairs with blacked-out trim. The tough coating resists scratches, fading and corrosion so it keeps its finish for years.
1Key UltraLock Security Tamper-resistant push-button locks sit recessed when locked, giving a quick visual cue your gear is secured. The 1Key UltraLock system lets you code multiple boxes on a truck, or a whole fleet, to a single key.
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 The box straddles the top bed rails behind the cab, keeping your bed floor open for sheet goods and cargo. Enhanced tie-down buckles and 12V PowerSync-ready access round out a box built for working trucks.
Reinforced Body, Automotive-Grade Hardware Weather Guard specifies a five-piece welded body for the 121-5-04, with a C-channel reinforced front panel and a heavy-duty C-channel reinforced lid, so the box stays square when it is loaded and when someone stands on the lid. The latch is an automotive dual-stage rotary mechanism, the same style a truck door uses, so it pulls the lid down onto the seal instead of relying on a friction catch. A welded gas strut shield keeps loose tools from knocking the strut mount out of line. The D-shaped ribbed weather strip is memory resistant, so it springs back after years of closing rather than taking a set and letting water track in.
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.
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, Gloss Black, in one place.
Warranty. Limited Lifetime Warranty from Weather Guard against defects in materials and workmanship.
Free shipping. This item ships free to the lower 48 states. Because it is an oversized item, it ships by freight and typically arrives in 3 to 7 business days.
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.
How the 1Key UltraLock System Works
A step-by-step look from Weather Guard at what the 1Key UltraLock actually does: how the cylinder accepts a new code, why the red push button retracts when the box is locked, and how the latch pulls the lid down against the seal. Worth two minutes before you set the box up.
How to Code Your 1Key UltraLock Lock
Weather Guard's official walkthrough for coding the lock so this box opens with the same key as the rest of your Weather Guard boxes. Follow it once when the box arrives and you can stop carrying a separate key for every lid on the truck.
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.
How the 1Key UltraLock System Works
A step-by-step look from Weather Guard at what the 1Key UltraLock actually does: how the cylinder accepts a new code, why the red push button retracts when the box is locked, and how the latch pulls the lid down against the seal. Worth two minutes before you set the box up.
How to Code Your 1Key UltraLock Lock
Weather Guard's official walkthrough for coding the lock so this box opens with the same key as the rest of your Weather Guard boxes. Follow it once when the box arrives and you can stop carrying a separate key for every lid on the truck.
Frequently Asked Questions
Straight answers on specs, fit and support
Will the 121-5-04 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 secure is this Weather Guard box?
It uses the Weather Guard 1Key UltraLock system with tamper-resistant push-button locks that sit recessed when locked, so you get a quick visual cue your gear is secured. The 1Key design also lets you code multiple boxes on a truck or a whole fleet to a single key.
Does the gloss black finish hold up to sun and weather?
Yes. The gloss black ARMOR TUF powder coat is a hard, UV-stable and corrosion-resistant coating, and the full-perimeter D-shaped weather seal keeps the contents dry. It resists chips and fading through seasons of loading and road spray.
Will the gloss black finish scratch or show dust easily?
The gloss black ARMOR TUF powder coat is a hard, chip-resistant coating built for work trucks, so normal loading and unloading will not mar it easily. Like any glossy surface it can show fine dust, which wipes off with a quick pass of a microfiber cloth.
What is it made of and how big is it?
It is built from welded aluminum diamond plate with a gloss black ARMOR TUF powder coat. The exterior measures 72"L x 20"W x 18"H with 11.0ft³ of storage, and it ships at about 81.5 lb, so it is strong yet lighter than a comparable steel box.
What our customers say
4.8 · 144 reviews
5★1174★243★22★11★0
Photos from owners
+4
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.
B fuller
Verified
08/04/2026
Weatherguard
Fits well on 2500 ram truck
Jose
Verified
07/13/2026
Toolbox for work
Also, experience employees are excellent with service
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.
Jim Shurling
Verified
06/19/2026
Awesome product.
Great product. Looks great. Build well.
1MDP
Verified
04/28/2026
does this fit in my truck?
this toolbox fits a crew cab silverado, am disappointed that no one seemed to know what trucks their toolboxes fit in. the difference between the standard and low profile is the distance from overhang and bottom of toolbox, standard is around 11 inches and the low profile is 13 inches.
bob app
Verified
04/01/2026
Great box, well made
Great box, I had researched this for awhile, and finally found it at Trator Supply. Even better than the box was th customer service I got at the Belfast Maine store when I ordered it on line.
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.
Goofy question
Verified
02/02/2026
Great quality
Not a cheap toolbox (in quality or price). Having several toolboxes on different tricks over the years, this is easily the best built box I’ve had yet. Very sturdy.
Hoppy
11/19/2024
Easy installation, only took a few minuets. This Saddle Box is by far the highest quality
Easy installation, only took a few minuets. This Saddle Box is by far the highest quality tool box of it's type on the market today. I bought a new truck recently and had deceived since I was retired I didn't need a truck box any longer. Wrong! I had bought an under the seat storage compartment for the rear set of the crew cab. Another joke unless all you need is a place to store a winter jacket. So I decided to buy a tool box and so I began to look around and I'm telling you 95% of the boxes on the market today are cheap! and I don't mean price wise. I like my money's worth when I buy. And for my money there's no better box for a 1/2 ton pick-up than the weather guard 121-0-01. You can buy one or a dozen +1 friends you do get what you pay for.
Mandy
Verified
01/29/2026
Looks awesome on my rig and is very sturdy, room...
Looks awesome on my rig and is very sturdy, room for everything I need.
AB33437
Verified
01/08/2026
Great Box
Works well for me small but does the job.
John
Verified
09/17/2025
Great box after I put shims on the latch catch...
Great box after I put shims on the latch catch so the lid would shut
Mace
Verified
04/07/2025
I have had a number of Weatherguard tool boxes over the years, and this one lives up to th
I have had a number of Weatherguard tool boxes over the years, and this one lives up to the standards I’ve come to expect from them. Installation requires no drilling on your truck, which is a big plus. I prefer the matt black finish because it keeps the box from becoming a large reflecting mirror in bright sunlight. I would like to see a system to keep the tool tray from sliding around, but that’s a minor detail that’s easy enough correct yourself. The locking system is also very secure and the aluminum construction, is very lightweight.
austinbldr
10/18/2024
Good Quality Box
I am a superintendent for a home builder, so it was important to me to buy a secure box that would protect my tools from theft and the elements. Riding around with all your tools in the box seat becomes a burden when you actually want to use the seats for passengers. I keep all of my hand tools, power tools, and supplies in the weatherguard box. Sure the Husky and Colbalt boxes have a nice price, but they certainly are not secure and typically have latching issues. You get what you pay for. Weatherguard does an excellent job.
Damian
Verified
01/08/2025
Fits great looks fantastic well made the only problem with...
Fits great looks fantastic well made the only problem with the anchor bolts didn’t sit quite flush due to the bed angle. Just have to see how well it lasts but looks fantastic thank you very much
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
Greg937
Verified
12/31/2024
Nice Box
I'm very satisfied with the product. I bought a few weeks back and put this on my 2018 Ford F150. I like the size, works well and looks great
Dnye
Verified
10/26/2024
Solid box and easy mount
Solid box. Lower profile makes rear truck window easier to see out. The new lock system is a step up from my other boxes.
JRMTZ
Verified
07/02/2024
A quality product at the right price
I'm very satisfied with the product. It has all the features I was looking for.
Mh123
09/26/2024
Very Good Tool Box
Well made. The quality is worth the money. I would buy again.
Trouble
Verified
06/01/2024
Best Built Box
This is the best built toolbox I have ever owned. Lid opens and closes smoothly and locks securely.
Dale
Verified
01/14/2024
Great toolbox
Well built toolbox but worth ever penny keeps tools dry and safe
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.
1up1
08/20/2024
Always a great product from weatherguard
.......... ....
HomeDepotCustomer
Verified
02/07/2024
The top seal was not consent in measurements on one of the corners
HomeDepotCustomer
Verified
07/10/2025
Perfect tool box and great size for my truck
Perfect tool box and great size for my truck
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.
C Booher
Verified
08/28/2026
Awesome!!!
Love this toolbox, compliments on it everywhere i go
Nate
Verified
08/22/2026
Way better than by backseat floor board!
Convenient storage
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.
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
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
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
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.
HomeDepotCustomer
Verified
07/13/2026
Love it. Will never buy a cheap toolbox again!
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.
Scott
Verified
07/07/2026
Superb box!
Went to TC to purchase a truck box. So many models out there in the 400+ range, but this one's reputation and quality was obvious. Well built, perfect powder coating and looks awesome on my 3/4 ton truck.
Jonathan
Verified
07/07/2026
Tool box
Perfect fit, allows my 5th wheel to go over it when I turn sharply
HomeDepotCustomer
Verified
06/27/2026
One of the best truck boxes . Great locking mechanism.
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!
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.
Anonymous
08/13/2025
Weather Guard
Worth the extra money compared to cheaper truck boxes!!
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…
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.
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
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
Well duh huh
Verified
06/18/2026
Locks
The locks our not as good as the ones on my older box weather guard