Procomp Electronics valve locks are wider-angled 10 degree locks. They distribute the ever-increasing valve spring loads over the retainer better than typical 7 degree locks by reducing the chance of "pull-through" failure. They are machined from chromoly steel, heat-treated for maximum strength, and designed with a 10 degree taper. The Procomp Electronics valve locks will fit any Procomp Electronics 10 degree retainer and are recommended for all race applications due to their superior strength.