Heat treated alloy tool steel, one inch base fits wrench or bench vise. The FR-5.2GT is designed specifically for use when removing and installing cassette lockrings from thru axle hubs.Cassette Lockring Tool with 12mm Guide Pin:Utilizes a 12mm guide pin to stabilize the tool in useFits 12-spline cassette lockrings from Shimano®, SRAM® (including 1x), SunRace®, SunTour®, Chris King® and others (23.5mm diameter)Fits some Shimano® and similar disc brake rotor lockringHeat 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-5.2G has 12 splines that are approximately 23.4mm across.Cassette Lockring Tool with 5mm Guide Pin:Fits Shimano®, SRAM® (including 1x), SunRace®, SunTour®, Chris King® and other cassette lockringsAlso fits some Shimano® disc brake lockringsGuide pin stabilizes tool