Genuine OEM Volkswagen Engine Crankcase Valve, part number 07Z129102B. This critical valve is responsible for regulating pressure within the engine crankcase, preventing the buildup of harmful gases and maintaining optimal engine operation. It plays a vital role in the vehicle's emissions control system by recirculating blow-by gases. Constructed from durable plastic, it weighs approximately 0.3 kg. Installing a genuine OEM crankcase valve ensures precise pressure regulation and proper sealing, which is crucial for engine longevity, preventing oil consumption, and meeting emissions standards.