A retainer is a mechanism that positions, as a device, frame, or groove that restrains, holds in place, or guides. A retainer may be also be a clip, bracket, or similar component that prevents a part within a machine from moving. A mechanical seal is a device that helps join systems or mechanisms together by preventing leakage e.g. in a pump system, containing pressure, or excluding contamination. The effectiveness of a seal is dependent on adhesion in the case of sealants and compression in the case of gaskets or orings. Specifications. Height 0.32 in.. Width 1.95 in.. Length 1.95 in.