Genuine OEM BMW Brake Vacuum Hose, part number 11667551621. This hose is responsible for delivering the necessary vacuum pressure from the engine source to the brake booster assembly to assist with braking force. It features pre-molded bends and factory-standard quick-connect fittings. Genuine OEM hoses are manufactured with specific heat-resistant and oil-resistant materials to prevent leaks and ensure the correct vacuum signal is maintained for reliable braking performance.