Key Features: The LRT-1 is designed and built to remove and install the lockring that retains the front chainrings found on Bosch® Gen 2 e-bike motors after crank arm is removed,Fits Bosch® Active Line (chainrings less than 20 teeth), Performance Line and Performance Line CX models,For lockrings with 50mm outside diameter with 8 notches,Replacement for Bosch® 0275009003 tool,Torque wrench compatible 3/8\" square drive,Constructed of 4140 heat treated steel and plated for long life.