Racing Head Service (RHS) 1634-16 Features: Cast 8650 Chromemoly Steel Body Arched Web-Like Design Increase Strength And Rigidity CAD/FEA Design Black Oxide Exterior Helps Prevent Corrosion Increased Retainer/Spring Clearance Lifetime Guarantee On The Rocker Body Height: 13.00 Width: 4.00 Length: 3.75 Weight: 9.14 lbs