Shimano TL-FC21 Crankset Dustcap Pin Tool with Chainring Nut Tool. Shimano Crankset Dustcap Pin Tool with Chainring Nut Wrench.3 claw end - Holds the slotted chainring fixing nut securely during the installation and removal of the chainring2 claw end - For installation and removal of the one key release crank cap133 mm over all length for better leverageCan be also used as 9 mm and 10 mm wrenchHardened steel for rigidity and durability