This Neilsen Flywheel Locking Tool is designed for Mercedes 1.8 and 2.1 Diesel engines (M651). It bolts in place of the starter motor to lock the flywheel, preventing it from turning when removing crankshaft front pulley fixings. This tool is applicable to various Mercedes models including A, B, C, CLA, E, GLA, GLK, and V Class from 2008 onwards, as well as light commercial vehicles like Sprinter, Viano, and Vito. It is equivalent to OEM part number 651 589 02 40 00. Manufacturer: Neilsen.