This Vestil TB-20 trailer/crane bumper is 6" in length, 3-1/2" wide, and is used to prevent damage to a loading dock from a trailer or crane. The pad has a depth of 3-1/2" and is made of molded rubber for elasticity and resistance to impact and weather. The material is Fiber reinforced prime rubber containing nylon resists abrasion, impact, wear and corrosion. This bumper has pre-drilled, countersunk 1/2" mounting holes for easy installation.