The Park Tool FR-5.2H is a reliable, professional option for bicycle cassette lockring removal and installation, with a long sturdy handle and a large passthru hole that allows use without removing most quick-release skewer nuts. The FR-5.2H fits 12 spline 23.4mm diameter tool fittings - the most common tool fitting found on 7-12 speed bicycle cassette lockrings, including most models made by Shimano, SRAM, SunRace, SunTour, Chris King and others. Also fits Shimano disc brake lockrings with 12 internal splines, and top caps of some Rock Shox suspension fork models including Pike, Lyrik, SID, Revelation, Reba, and Paragon. The FR-5.2H has 12 splines that are approximately 23.4mm across at the widest point. Center bore for axle or Q/R nut clearance is 20mm.