The Shimano SLX SM-RT66 disc brake rotor uses anti-loosen plate construction to keep its mounting bolts secure through repeated riding, cutting down on the bolt checks a standard rotor often needs. Installation goes quickly since the plates hold the bolts in place from the first tightening, and the rotor works with either resin or metallic pads, so a pad swap down the line doesn't mean a rotor swap too. Details 180mm, 6-bolt disc brake rotor Compatible with resin or metal brake pads One-piece rotor construction Includes rotor fixing bolts and non-turn washers