Extruded or molded profiles comprising a polyolefin composition consisting of 85% by weight or more of a copolymer of 1-butene with ethylene (A) having an ethylene copolymerized content up to 18% by mol, and having Mw/Mn lower than 3, hardness shore A (measured according to ISO 868) lower than 90, no melting point (TmII) detectable at the DSC after cancelling the thermal history, melting enthalpy (ΔHf), measured by DSC after 10 days of aging at room temperature, comprised between 4 and 15 J/g; and up to 15% by weight of a propylene copolymer or a composition of copolymers of propylene (B) having a melting point from about 126° C. to 200° C., isotactic index greater than 90%.