The Genuine BMW Door Lock Cylinder - 51218244052 is a replacement part for the door lock system of BMW vehicles. It is a cylindrical component that is designed to fit into the door handle and allow for the locking and unlocking of the door. This product is made by BMW and is an authentic, high-quality replacement for damaged or malfunctioning door lock cylinders. It is compatible with various BMW models and is made from durable materials to ensure long-lasting performance.