Description The Park Tool Cassette Lockring Tool FR5.2G features an added 5mm guide pin to stabilize when used on QR hubs. The FR-5.2G is designed to fit the most common tool fitting found on 7-to-12 speed cassette lockrings, including models made by Shimano, SRAM, and others. Also fits disc brake lockrings and lockring adapters with 12 internal splines. Thin wall construction allows use without removal of cones and locknuts. The 1″ hexagonal base can be used in conjunction with a socket, wrench, or bench vice. Heat-treated alloy tool steel construction for a lifetime of use. Park Tool Cassette Lockring Tool FR5.2G features & specs Fits 12-spline tool fittings with an approximate outer diameter of 23.4 mm including: Cassette lockrings from Shimano, SRAM (including 1x), SunRace, SunTour, Chris King and others Disc brake lockrings and lockring adapters with 12 internal splines from Shimano and other brands For instructions on how to remove & reinstall your cassette check out this video from Park Tool.