Used to remove the cassette lockring when bike shop resources are not available, this tool secures the lockring from turning by locking it to the dropout so that when the cranks are turned with the bike in low gear the pedaling force will actually break the lockring free. It is designed primarily for emergency use. The tool can be used in reverse to be able to install the lockring as well. Shimano compatible - not for Campagnolo.

Tool Instructions