Universal Air Filter with Carbon Fiber Top and Base (KNNRP-5135)Description The RP 5135 Universal Air Filter is constructed from an oiled cotton filter media. It comes with a K&N embossed carbon fiber top and carbon fiber base for strength and durability. The carbon fiber element adds to the light weight design and gives this filter a smooth glass like finish. The RP 5135 is a clamp on filter that has an inside flange diameter of 3 5 16 inches and a flange length of 2 inches. The base is 18 3 4 inches by 5 inches