Pro-One 1-Piece Rear Rotor With Directional Holes For Harley Big Twin Features This polished stainless steel rotor replaces stock rotors perfectly Made from stainless steel Polished to a beautiful shine Holes are drilled through the disc to keep the disc from getting hot Very nice quality ! Holes are drilled in a directional pattern to assure that they are quiet when braking at low speeds and it gives the rotor a nice look