Tuxihapp Roof Box U-Bolt Clamps 4PCS Stainless Steel Mounting Kit — 83mm/103mm U-Bolts, Rubber Washers

This Tuxihapp kit includes four U-shaped stainless steel bolts, rubber washers, backing plates, lock nuts, two reinforcement straps and a hole-sealing sticker. Built for repeated use in changing weather, the components combine metal strength with cushioning rubber and plastic to protect both your roof box and vehicle crossbars. Installation is straightforward and designed to fit common crossbar widths, making it a practical add-on for weekend trips or daily cargo needs.

How do these U-bolt clamps attach to my roof box and crossbars?

The clamps loop around your vehicle crossbar and bolt through the roof box mounting points using the supplied backing plates and lock nuts. Rubber washers cushion contact points to reduce wear and block vibration, while the lock nuts secure fitment under load.

• Four stainless-steel U-bolts sized with 83mm inner width and 103mm outer width
• Backing plates and 8 lock nuts for tight, reliable fastening
• Rubber washers to protect paint and absorb vibration
• Two reinforcement straps to stabilize the box on rough roads

Will this mounting kit fit my vehicle’s crossbars?

Measure your crossbar width before buying: the U-bolts accommodate crossbars up to about 3.34 inches wide. The kit is compatible with most sedans, SUVs and off-road vehicles that use standard roof box mounting holes and crossbar sizes within that limit.

• Inner bracket width: 83 mm (3.27 in)
• Outer bracket width: 103 mm (4.04 in)
• Works with crossbars up to 3.34 in wide—check your crossbar profile
• Includes a sealing sticker for neat hole coverage

How durable and weather-resistant are the components?

Key parts are stainless steel with plastic and rubber elements chosen for corrosion resistance and wear durability. The materials resist typical road exposure—rain, salt spray and UV—so the kit remains dependable across seasons when properly installed and inspected.

• Stainless-steel U-bolts resist rust and retain strength
• Plastic back plates won’t deform easily under torque
• Rubber washers buffer impacts and reduce noise
• Lightweight parts are easy to store when not in use

How quick is the installation and what tools are required?

Most users finish installation in 3–5 minutes per U-bolt with basic hand tools. No advanced skills are needed: align the U-bolt, add washers and backing plate, and tighten the lock nuts to secure the box. The included straps help keep the box stable while you fasten everything.

• Estimated install time: 3–5 minutes per clamp for an experienced do-it-yourselfer
• Requires common wrenches or a socket set for lock nuts
• Clear instructions and pre-measured parts speed fitting
• Sealing sticker covers any visible holes for a finished look

Who is this for? The Tuxihapp 4PCS Roof Box U-Bolt Clamps are for drivers who already use a rooftop cargo box and want an easy-to-install, corrosion-resistant mounting upgrade. It's a practical choice for weekend adventurers, families needing extra trunk space, and anyone who wants added stability and reduced vibration for rooftop cargo without modifying crossbars permanently. Verify your crossbar width before purchasing to ensure a secure fit.