We now sell the white plastic gear that Mercedes never has made available. Instead of buying the entire arm/transmission assembly, just buy the plastic horseshoe-shaped gear and make this repair easily. Arm assembly and screws not included. Note: This gear only works on Bosch brand wiper arm/transmission assemblies, it does not work on SWF brand assemblies. The correct Mercedes parts numbers this gear works on are 124-820-23-07,124-820-25-07, 001-820-12-07, & 201-820-07-07.