Genuine OEM BMW Crankshaft Bearing Shell, part number 11211717779. This precision-engineered shell supports the crankshaft, reducing friction and wear during engine operation. It is manufactured to exact tolerances to ensure proper oil clearance and load distribution. Genuine OEM bearings are critical for engine longevity, as they are calibrated to specific material hardness and dimensions to prevent vibration and premature failure under high-stress conditions.