This Recirculating valve is for the Mercedes 2.0 Turbo GDi engine found in the CLA250 that has the electronically controlled bypass valve. It is recommended for any vehicle where the boost pressure has been increased by an ECU software upgrade and for unmodified vehicles operating in warmer climates, as a solution to the many failures that have occurred where the original rubber diaphragm splits, which causes a loss of boost pressure. Unfortunately the failure doesn't always result in a check engine light as the valve can still be blown open by the boost pressure, so you may not be aware that you are losing power due to this. Our alternative is a fully engineered solution offering significantly improved reliability. Our valve is piston based with no diaphragm to fail, and of all aluminium construction. It replaces the original unit with a pressure/vacuum operated piston valve that still also retains the desirable OEM ECU control over valve actuation. All parts require for installation are included, together with full installation instructions. All Forge Motorsport products come with a limited lifetime warranty. All warranty claims must be accompanied by the original proof of purchase to enable us to help you. Failure to supply this proof will result in your claim or enquiry being denied.