O-ring, metric, nitrile, black, 70-75A shore, 4 x 26 mm, Dichto.

An O-ring, also known as a packing, is a mechanical gasket. it is a loop of elastomer with a round cross-section, designed to be seated in a groove and compressed during assembly between two or more parts, creating a seal at the interface. The O-ring may be used in static applications or in dynamic applications where there is relative motion between the parts and the O-ring. O-rings are one of the most common seals used in machine design because they are inexpensive, easy to make, and reliable and have simple mounting requirements. Nitrile, also known as Buna-N or acrylonitrile butadienerubber, is typically used for general sealing purposes,which includes sealing of hydraulic fluids, petroleum oils, water and so on.