RCP- Workshop quality for the home. The RCP FR-20 Cassette Lockring tool is an indispensable basic tool for all hobbyists who want to take care of their bicycle maintenance themselves. Equipped with a central pin, it is ideal for removing rear sprockets with a quick release axle. The medium sized mandrel fixes the tool in position, thus ensuring that the tool slip. In combination with a large, open-end wench and a chain whip, for example the RCP chain whip, all the standard Shimano spocket sets at the rear freehub body can easily be asssembled or disassembled. Please note: For rear wheels with a traditional screw axle the RCP FR-20 is not suitable. Please see instead the RCP FR-10.