For a low-key, stealth look, the Weather Guard 121-52-04 comes in a textured matte black ARMOR TUF finish that kills glare and hides fingerprints, dust and light scratches. It is the finish to choose if you want your gear locked down without drawing attention. It is the pick for anyone who wants a tactical, low-shine look that hides marks and still wipes clean fast. The flat, non-reflective surface also cuts down on the sun glare that bounces off a bright bed. 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 matte 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 textured matte black ARMOR TUF powder coat.
Textured Matte Black ARMOR TUF Finish A textured matte black ARMOR TUF powder coat gives a low-glare, blacked-out look that hides fingerprints, dust and light scratches better than a glossy coat. It is the stealth choice for a clean, understated truck.
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 121-52-04, 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, Matte 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.
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.
Compare The Range
How this compares to similar models
The closest alternatives side by side, so you do not have to keep tabs open.
Model
This OneWeather Guard 121 Aluminum Crossover Truck Tool Box, Full-Size Low-Profile, Matte Black (121-52-04)
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 121-52-04 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.
Will the matte black finish fade or stain in the weather?
No. The textured matte black ARMOR TUF coating is built to resist UV fading and corrosion, and the full-perimeter D-shaped weather seal keeps rain and dust out. Its low-sheen texture also helps hide water spots and road grime between washes.
Is the matte black finish good at hiding marks?
Yes. The textured matte black ARMOR TUF coating is designed to diffuse light, so fingerprints, dust and minor scuffs are far less visible than on a bright or gloss finish. It gives the box a durable, low-maintenance stealth look.
What is it made of and how big is it?
It is built from welded aluminum diamond plate with a textured matte 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.
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