This FFKM - FFPM O-Ring is 11.91 x 1.78mm and in the color Black. The Hardness of this O-ring 11.91x1.78 FFKM - FFPM - FDA - USP Class VI - 3A Sanitary - Kalrez 6230 - 70 Shore A - Black - ORS220819 (Equivalent) is 70 Shore A.The alternative names of the compound are FFPM � Dupont Kalrez and they are mostly produced by 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 -25 ºC to 270 ºC. O-rings 656187 are indicated as 220819 and have a DIN 3771 Size of 11.91 x 1.78. This item is equal to Dupont Kalrez 6230, Freudenberg Simriz 491 and has an Approval. The chemical name of this Oring is Perfluoroelastomer.