Rev9Power Rev9_BOV-006-BLACK; RS-Series 50mm V Band Blow Off Valve(Black) Product Details Project's Black RS Series 50mm V band blow off valve (BOV) (includes a V band adapter) "-Universal 50 mm V band clamp BOV -8 psi spring -Includes a weld-on aluminum flange and V band clamp -Perfect for all turbo application -Simple one step process to remove and installing different BOV springs -Distinctive tone Application : 400-800 hp