Valve springs with larger diameters require retainers to handle the higher pressures developed by the springs. COMP Cams steel retainers are precision machined from 4140 chromemoly steel and finished in black oxide. These precision retainers are specifically designed for positive location when combined with COMP Cams high-quality valve springs. For superior strength and ultimate stability, both 7? and 10? retainers and valve locks are available.