Specification: Material: Stainless Steel, Rubber, Plastic Quantity: 4 PCS Color: Black Weight: 1.85 lb Size: 3.8×2.6 inches Package Includes: 4 U-Bolts, 4 Back Plates, 2 Straps, 4 Gaskets, 8 Lock Nuts, 1 Sheet of Hole Sealing Sticker Feature: Practical, Durable, Sturdy Fit Type: Universal Fit Why do you need these roof box u-bolt clamps? -The straps included with this U-bolt clamp are long enough to securely fasten the roof box to the car roof. -Each accessory is lightweight and small in size, so it can be easily stored in the trunk and taken out whenever you need it. -This stainless steel rack clamp has excellent corrosion resistance and wear resistance, and can withstand complex weather conditions.