Precisely machined for a perfect fit, this 8-notch tool removes and installs the lockring that retains front chainrings found on Bosch Gen 2 e-bike motors after the 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 and 8 notches - Replacement for Bosch 0275009003 tool - Torque wrench compatible 3/8-inch square drive - Constructed of 4140 heat treated steel and plated for long life