1.Quick Release Design: The knobs allow you to quickly get your traction boards without any tool. 2.Bolt-on Installation: These traction board mounting pins can be easily installed with all necessary hardware included in the package. 3.Perfect Fitment: With this mounting kit, traction boards can be attached to a roof rack or truck bed rack with M10 holes. 4.Efficient:Provides emergency traction for your auto tires, gets the auto of snow, ice, mud or sand. 5.Material:Made of high quality steel, sturdy and . Strong structure, with fine workmanship,high strength and solid. Easy to Installed:Simplify installation steps, without modification, no installation instruction. Colour:Black&Silver Material:Plastic + stainless steel Package Contents: 4 x bolts 2 x boards Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.