Heat treated alloy tool steel, one inch base fits wrench or bench vise. Thin wall construction allows use without removal of cones and locknuts. The FR-5.2 has 12 splines that are approximately 23.4mm across. - Fits Shimano, SRAM, SunRace, SunTour, Chris King and other cassette lockrings - Fits the SRAM XX1 11-speed cassettes - Also Fits Shimano disc brake lockrings