This FFKM - FFPM O-Ring is 18x4mm and in the color Black. The Hardness of this O-ring 18x4 - FFKM - FFPM - FDA - USP Class VI - Kalrez 6230 - 75 Shore A - Black - ORS84646 (Equivalent) 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 -20 ºC to 270 ºC. O-rings 606841 are indicated as 84646 and have a DIN 3771 Size of 18x4. This item is equal to Dupont Kalrez 6230, Greene Tweed Chemraz SD625 and has an FDA - USP Class VI - 3A Sanitary Approval. The chemical name of this Oring is Perfluoroelastomer.