This item is made of durable plastic. It does not come with a bolt and U-nut required to replace the shorter OEM model that is installed in the vehicle's rear fender. The description says no drilling is required, which is correct for the front wheels if you don't want to accommodate a fifth wheel. spigot, then you need to drill an extra hole in the fender. However, the rear wheels need to be drilled (3 holes in each area of the wheel) to mount the fenders. For the price, this is a great addition.