A polyolefin composition made from or containing:T1) 70-95 wt %, of a polyolefin component containing: a1) from 30 wt % to 70 wt % of a propylene based polymer; and a2) from 30 wt % to 70 wt % of an ethylene based polymer; and T2) 5-30 wt % of a polyolefin component containing: A) 5-35% by weight of a propylene homopolymer or a propylene ethylene copolymer; B) 25-50% by weight of a copolymer of ethylene and a C3-C8 alpha-olefin containing 0.1-20% by weight of C3-C8 alpha-olefin units; and C) 30-60% by weight of a copolymer of ethylene and propylene containing 25-75% by weight of ethylene units.