This FFKM - FFPM O-Ring is 158x6mm and in the color Black. The Hardness of this O-ring 158x6 - FFKM - FFPM - 75 Shore A - Black - Kalrez® 6375 - ORS62704 (Equivilent) is 75 Shore A.The alternative names of the compound are FFPM � Dupont Kalrez and they are mostly produced by Evolast� - Chemraz� - Simriz� - Kalrez� - Spectrum - Triazinico - Isolast� - Parofluor� - Fluorez - Perlast� - HPSealing� - Perfluor� - Polymax. The O-ring is commonly used in and has an operating temperature range from -20 ºC to 270 ºC. O-rings 535547 are indicated as 62704 and have a DIN 3771 Size of 158x6. This item is equal to Dupont Kalrez 6375, Freudenberg Simriz 495, Greene Tweed Chemraz 605, PPE Perlast G80A, Parker Parafluor V8910-75 and has an General Purpose (+270?C) Approval. The chemical name of this Oring is Perfluoroelastomer.