Chainring lockring tools from Park Tool.

• Integrated 3/8" drive fitting allows compatibility with most ratchet handles and torque wrenches for tightening to proper torque specifications
• Heat-treated and plated 4140 steel construction ensures durability and long life
• Fits lockrings with 50 mm outside diameter and 8 notches
• Replacement for Bosch 0275009003 tool
• Removes and installs the front chainring lockrings found on DJI Avinox & Bosch Gen 2 e-bike motors once the crank arm is removed