The present invention relates to a polymer composition, comprising: (i) a polypropylene matrix; (ii) a first elastomeric phase dispersed within the matrix and having a glass transition temperature Tg1, measured with dynamical mechanical thermal analysis according to ISO 6721-2, wherein the first elastomeric phase comprises an ethylene copolymer having comonomer units derived from C3 to C8 olefins; (iii) a second elastomeric phase dispersed within the matrix, wherein the second elastomeric phase is crosslinked and has a glass transition temperature Tg2, measured with dynamical mechanical thermal analysis according to ISO 6721-2, within the range of −70° C. to −90° C., wherein the difference between Tg1 and Tg2 is at least 15° C. and Tg1 is higher than Tg2.