Genuine OEM Audi Front Left Seat Belt Pretensioner, part number 4M0857619A. This critical safety component is engineered to rapidly tighten the seat belt in the event of a collision, securing the occupant more effectively. It is installed in the front left seating position. Weighing 0.509 kg and measuring 0.39m in length, this pretensioner is built to precise safety standards. Choosing a genuine OEM seat belt pretensioner ensures correct activation timing, reliable performance, and integration with the vehicle's safety systems, which are paramount for occupant protection.