The Park Tool FR-5.2GT incorporates a specially-sized guide pin that stabilizes the tool when removing cassette lockrings from 12mm thru-axle hubs. Fits 12-spline cassette lockrings from Shimano ®, SRAM®, SunRace®, SunTour®, Chris King® and others (23.5mm diameter). Fits some Shimano® and similar disc brake rotor lockrings.