Genuine BMW Drive Belt Idler Pulley (80mm) - 11287500560: Genuine BMW Drive Belt Idler Pulley (80mm) - 11287500560 is a genuine BMW part designed to replace the original part on your vehicle. It is made from high-quality materials and is built to last. This pulley is designed to help keep your drive belt tight and improve engine performance. It is an essential part of your BMW's maintenance and replacement needs.