This FFKM - FFPM O-Ring is 8.5x2.8mm and in the color Black. The Hardness of this O-ring 8.5x2.8 - FFKM - FFPM - High Temp - 75 Shore A - Black - Kalrez® 4079 - ORS77807 (Equivilent) is 75 Shore A.The alternative names of the compound are FFPM – Dupont Kalrez and they are mostly produced by Kalrez® - Simriz® - Chemraz® - Spectrum® - Triazinico® - Isolast® - Parofluor® - Fluorez® - Perlast® - Perfluor®. The O-ring is commonly used in and has an operating temperature range from -15 ºC to 330 ºC. O-rings 573393 are indicated as 77807 and have a DIN 3771 Size of 8.5x2.8. This item is equal to Dupont Kalrez 4079, Freudenberg Simriz 498, Greene Tweed Chemraz 615, PPE Perlast G75B, Trellebrog Isolast J8325 & Isolast J9876, and has an General Purpose (+330˚C) Approval. The chemical name of this Oring is Perfluoroelastomer.