Universal 50mm V- Blow Off va-lve Dump va-lve BOV with Aluminum Flange Feature: The Blow-Off va-lve (BOV) is a pressure relief device on the intake tract to the turbo's compressor from going into surge. When the throttle is closed rapidly, the airflow is quickly reduced, causing instability and pressure fluctuations. Surge can eventually lead to bearing failure due to the high loads associated with it. Blow-Off valves use a combination of manifold pressure signal and spring to detect when the throttle is closed. When the throttle is closed rapidly, the BOV vents in the intake tract to to relieve the pressure, helping to surge. Specification: Material: Machined Billet Aluminum Body Color: Red/ Blue/ Black/ Sliver Flange Diameter: 50mm Fitment: Universal Package Content: 1 X Blow Off va-lve 1 X Aluminum Flange 1 X V- Clamp 1 X Set Of O-rings And Bolts , Gaskets.