Made from Ethylene, Propylene, and Diene Monomers and is a very versatile and durable type of rubber with many applications Temperature Range: -55°C (-67°F) to 125°C (257°F); Shelf-life: 15 Years These versatile o-rings perform well in alcohols, automotive brake fluid, ketones, dilute acids & alkalis, silcone oils & greases, steam up to 204.4°C (400°F) Durometer (hardness) of 70A for resistance to penetration O-ring Size meets standards defined by AS568A (b) ID (Nominal): 1-3/4 ID (Nominal): 3/16 CS (Nominal): 2-1/8 OD