Bosch aluminium lock ring for chainring

Bosch aluminium lock ring for chainring. Replacement needed if you worn or damaged the original lock ring of your Bosch electric motor.

- Model 1: Old Classic+.

- Model 2: For Active, Performance, Performance CX (BDU2xx).

- Model 3: For 3th generation Active Line and Active Line Plus (BDU3xx).

- Model 4: For 4th generation (BDU4xx).

- Model B: Same as Model 2 (BDU2xx) but for chainrings with offset (Boost).