Yes, steel belt. I don't think many models, if any, use rubber belt since the 1958 Daf. Nothing to worry, it's a Toyota-Aislin unit. They have been producing CVTs for 16 years (5 for the current Corolla units - 3 in NA) without any surge/pattern in complaints (GM-Fiat, Nissan, Honda and Audi can't say the same !).