A rubber composition, comprising i) an ethylene-α-olefin-non-conjugated-diene copolymer having—a Mooney viscosity ML (1+8) at 150 ° C. ≥85 MU and—an ethylene content≤63 wt. %—the diene content is 4 to 8% by weight of the ethylene-a-olefin-non-conjugated-diene copolymer i), —the non-conjugated diene is a combination of 5-ethylidene-2-norbornene (ENB) and 5-vinylnorbornene (VNB), —the ethylene-α-olefin-non-conjugated-diene copolymer i) has an amount of VNB between 0.05 and 1 wt. %, and has a Mw of at least 400,000 g/mol and, ii) an extender oil of 10 to 40 phr based on the copolymer i) with the sum of the EPDM copolymer i) and the oil ii) amounting to at least 95 wt. % of the composition.