Park tool bottom bracketcassette tool bbt5fr11this tool is designed to remove lockrings from campagnolo cassettes it is made from heat treated alloy tool steel that makes it durable and long lasting a one inch base fits a wrench or bench vice and thin wall construction allows use without removal of cones and locknuts for ease of use features fits all campagnolo cassette lockrings also fits campagnolo record chorus centaur and athena bottom brackets the outside diameter of the bbt 5