The Shimano Deore XT RT-MT800 centerlock disc brake rotor features an advanced heat sync design. FEATURES: Rotor construction uses Shimano FREEZA technology to boost heat dissipation and reduce fade Easy disc brake rotor installation with spline mount and lock ring Compatible with metal and resin brake pads SPECS: Rotor Type: Two Piece Hub/Disc Compatibility: Center-Lock Disc Pad Compatibility: All Pad Compounds Internal Lockring: Compatible with axles 12mm or smaller only External Lockring: Compatible with all axle sizes including 15 and 20mm through axles