Wastegates provide a means to control the boost pressure of the turbo charged engine. Wastegates work to bypass exhaust flow from the turbine wheel. Bypassing the exhaust flow reduces the power driving the turbine wheel to match the power required for a given boost level. Similar to the BOV, the Wastegates uses boost pressure and spring force to regulate the flow bypassing the turbine. Wastegates are bolted to exhaust manifold or header. The advantage of external Wastegates is that the bypassed flow can be reintroduced into the exhaust stream further downstream of the turbine. This tends to improve the turbine’s performance. FEATURES & BENEFITS : 100% Brand New. Never been Tried or Installed Unadjustable-35mm, 38mm, 40mm, 44mm, 50mm, 60mm, Adjustable-35mm, 46mm, 60mm. EXACTLY the same as the picture below All Cast Steel Body with Steel Head No instructions included. Professional installation is highly recommended. APPLICATION: suitable for all turbocharged vehicles with an external wastegate turbo system For prices and model, please contact us for more information.