Center Lip: 57

Equipped with Patent Pending Zero-Backdrive gearbox technology

There are no springs

\n2 x 1/8 NPT Hose Tail Fittings

BOV ProPort GenV Supercharger Black Touch Up Paint Center Lip: 57ProPort by Turbosmart is an All New 54mm (2. 13in) Blow Off Valve with a tiny footprint and massive flow. The ProPort flows 420 cfm which is enough for 3500 HP and is in a league of its own standing 30mm (1. 2in) lower than PowerPort while flowing over 25% more than the Market leading 50mm Raceport. Features include our unique locking collar design, new unique vent profile, sensor cap option and spring options for all turbocharged and supercharged