1-1/2" x 1-3/4" x 1/8" Rubber O-Rings 6PK, Midwest Fastener, Mfr#: 64844

An O-ring is a mechanical gasket in the shape of a torus; it is a loop of elastomer with a disc-shaped cross-section, designed to be seated in a groove and compressed during assembly between two or more parts, creating a seal at the interface.