This NBR - Nitrile O-Ring has a diameter of 691x5.7 mm and is Black in color. The hardness of this O-ring 691x5.7 - NBR - Nitrile - 70 Shore A - Black - ORS308851 is 70. Alternative names for the compound are Nitrile Rubber - NBR, and it is commonly produced by Perbunan® | Krynac® | Nipol® | Europrene N® | Breon® | Chemigum® | Nysyn® | Kalar®. The O-Ring is typically used in and has an operating temperature range from -30 ºC to 100 ºC. O-Rings 477156 are referred to as 308851 and have a DIN 3771 size of 691x5.7. This item is equivalent to and has an approval. The chemical name of this O-Ring is Acrylonitril-Butadiën-Copolymeer / Buna-N.