Abstract: A seal/retainer unit (10) comprising an annular sealing gasket (12) and a plurality of retaining legs (14) extending generally perpendicularly therefrom. The sealing gasket (12) and the retaining legs (14) are formed in one piece (e.g., stamped) from a sealing material and dimensioned to allow nesting of a plurality of seal/retainer units (10) in a stacked arrangement. The retaining legs (14) may each include a rounded distal edge (16) to minimize package-tearing and interpart-marking and/or a break-off notch (18) to allow special customization. A radiused corner (20) between the gasket (12) and the legs (14) assures a gap between nested parts.