This retainer is used in all EATON supercharger oil-filled nose drives (also called drive covers) to retain the seal.
Only use genuine EATON parts in your supercharger. Your EATON supercharger is a precision instrument built to exacting tolerances. Seals, retainers, and bearings in particular all need to fit precisely in order to keep your supercharger spinning reliably. Always use the correct Eaton Supercharger Oil whenever you change the oil to work on the supercharger internals.
Eaton Part number: 100500