Product Description Specifications Precision machined from chromemoly steel then black oxided, these 10 degree retainers are designed specifically 1.500"-1.550" O.D. valve springs such as our 911, 932, 26115 and 935 valve springs. Category: Engine Components>Valve Springs, Retainers Core: N LTL: N MPN: 748-16 Proposition 65: Y Special Order: Y