This is for an upgraded alloy Lock Ring that holds the front sprocket spider onto the motor drive pinion on the Bosch Active / Performance Drive Unit.
Substantially tougher than the plastic nuts, although be careful not to cross thread the nut on the drive unit assembly.
Remember it's reverse thread and only needs to be tightened to 20-25Nm.
We also sell the Bosch Active / Performance Spider Tool to safely remove and replace this nut. (See related products tab).
Just to confirm it's to fit the following motor shape. If you require a Classic+ lock ring, you can find it here.