VDF-based curable fluoroelastomers, having a glass transition temperature lower than −49° C., preferably lower than −50° C., and having the following composition, as percent moles: A) from 25% to 50%, preferably from 30% to 45%, of the monomer of formula: CF2═CFOCF2OCF3 (a); B) one or more (per)fluorinated comonomers having at least one unsaturation of ethylene type in amounts from 75% to 50%; preferably from 70% to 55%; said one or more comonomers comprising vinylidene fluoride (VDF) in amounts from 50% to 75% on the total of the monomer moles; the sum of the molar percentages of the monomers being 100%; said fluoroelastomers containing an amount of —COF end groups in the polymer lower than the sensitivity limit of the method reported in the description.