The Park Tool FR-5.2G Cassette Lockring Tool w/ 5mm Guide Pin melds the dependable design of the FR-5.2 lockring tool with a 5mm guide pin for extra stability when used with quick-release hubs. It is compatible with most 7-12 speed cassette lockrings. Features: 5mm guide pin adds stability when used with quick-release hubs Fits most 7-12 speed cassette lockrings Hex-shaped base of tool fits 1" (25.4 mm) socket or wrench. Can also be clamped in a bench vise Specifications: Outer Diameter: 23.4mm (Approximate) Guide Pin: 5mm Splines: 12 Compatibility: Fits 12-spline tool fittings with an approximate outer diameter of 23.4 mm Fits cassette lockings from Shimano, SRAM, SunRace, SunTour, Chris King, and more Fits disc brake lockrings and locking adapters with 12 internal splines (Shimano type)