The Shimano Deore SM-RT54 disc brake rotors provide exceptional stopping power in all riding conditions. Shimano's Center Lock mounting system makes installing and removing rotors quick and easy thanks to the spine mount and lock ring design.-For use with resin pads only-Center Lock lockring design offers fast and easy installation-Includes standard type rotor lockring-Requires external-type rotor lockring when installing onto 15/20mm axle hub