Fits: All valve covers with 1.25 holes; Manufactured from 6061 Billet Aluminum; Screws to valve cover for positive fit, does not push on; Designed in two pieces with a top that unscrews to allow for oil filling and easier cleaning or replacement of oil separator filter; Slip-on fitting for pan evac system; O-ring Seal no gaskets (reduces leakage); Meets rule requirement for cars running 7.99 E.T. and quicker