Competition Cams 612-16 Steel Super Locks, 10 degree Lock Angle for 3/8" Valve Stem Diameter with Lash Cap Recess Precision-machined rather than stamped for the ultimate in accuracy Super-tough, fatigue resistant alloy material Inside tang-to-taper relationship held tightly for repeatable valve spring installed heights For simplicity, any Super Lockfits any COMP Cams 10 degree retainer - just choose the correct lock for you valve size and application Super Locksare recommended in all race applications