Acrylonitrile/butadiene rubber is a heteropolymer with an acrylonitrile content of between 18 and 50%, although a mean content is often aimed for so as to achieve good resistance to oil and petrol along with the highest possible low temperature flexibility and elasticity. Depending on the actual composition, the material is resistant to low temperatures down to - 55° C. It displays higher resistance to abrasion than others elastomers, but is not resistant to weathering and ageing. For material characteristics materials for secondary seals.