This FFKM - FFPM O-Ring has a diameter of 660 x 7 mm and is Black in color. The hardness of this O-ring 660x7 - FFKM - FFPM - F909ZEX - AED - Norsok M710 - High Temp. (+320°C) - 90 Shore A - Black - ORS188671 is 90. Alternative names for the compound are FFKM – FFPM, and it is commonly produced by Kalrez® | Simriz® | Chemraz® | Perlast® | Isolast® | Parofluor®. The O-Ring is typically used in and has an operating temperature range from -15 ºC to 320 ºC. O-Rings 654588 are referred to as 188671 and have a DIN 3771 size of 660 x 7. This item is equivalent to and has an AED - Norsok M710 - Hoge Temp. (+320°C) approval. The chemical name of this O-Ring is Perfluorcarbonrubber / Perfluoroelastomeer.