This Silicone - VMQ - MVQ O-Ring has a diameter of 25x3 mm and is Red in color. The hardness of this O-ring 25x3 - VMQ - MVQ - SIlicone - FDA - EC1935/2004 - 70 Shore A - Red - ORS8297 is 70 Shore A. Alternative names for the compound are Silicone Rubber - PVMQ, and it is commonly produced by Eriks - Wacker - Eastern Seals - and BlueStar. The O-Ring is typically used in and has an operating temperature range from -50 ºC to 210 ºC. O-Rings 21507 are referred to as 8297 and have a DIN 3771 size of 25x3. This item is equivalent to and has an FDA 21 CFR 177.2600 - EC1935/2004 approval. The chemical name of this O-Ring is Vilnyl Methyl Silicone.