This NBR O-Ring has a diameter of  mm and is Black in color. The hardness of this Back-up Ring 165.71x177.69x2.97 - AS568-439 - NBR - Parbak® - Concave - 90 - Black - ORS275656 is 90. Alternative names for the compound are , and it is commonly produced by . The O-Ring is typically used in and has an operating temperature range from -30 to 135. O-Rings 66670 are referred to as 275656 and have a DIN 3771 size of . This item is equivalent to and has an approval. The chemical name of this O-Ring is Nitrile Butadiene Rubber.