Weather Guard 121 Aluminum Crossover Truck Tool Box, Full-Size Low-Profile, Matte Black (121-52-03)

$1,099.00 Regular price $1,173.99 Save $74.99
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Weather Guard Truck Box Hardware Installation Guide

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 Truck Box Hardware Installation Guide

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

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.