Function: use to lock the camshafat and crankshaft in a right position, when check the timing or replace timing chain. Applicable Engine: Compatible with Mercedes Benz OM654 1.6 2.0 diesel engine, engine code:1.6L 654.916, 2.0L 654.920. Applicable Vehicle Incluude: compatible with Benz A Class (from 2019), B Class (from 2019), C Class (from 2018), CLA (from 2019), CLS (from 2018), E Class (from 2016), GLB (from 2019), GLC Coupe (from 2019), GLE (from 2019), V Class (from 2019), Vito (from 2019). OEM Equivalent Part Number: W654 589 00 21 00, W654 589 00 40 00, W654 589 01 40 00. Durable: made of high hardness steel, strong and not easy bend, and all the tools put in a case, easy to carry and storage.