BOV Supersonic Maz/Sub-BlueThe Bov5 from Turbosmart is a 38mm positive seal piston style valve based on our motorsport proven boost balance technology which means the more boost you feed this valve, the better it seals Simple as that! Manufactured from Billet Alluminium and hand assembled with a precision matched piston for maximum possible response, each and every valve is tested to ensure correct seal and operation before being shipped and is capable of bypassing up to 800HP