Not to be confused with the Shimano cassette lockring remover - they look very similar. This splined freewheel remover will fit Regina and old-school Zeus and Atom freewheels. Also known to fit some, but not all older Schwinn freewheels. The heat treated steel is super strong and one inch base fits a wrench or bench vise. Thin wall construction allows use without removal of cones and locknuts.