Products for treating keratin-containing fibers containing, in a cosmetically acceptable carrier, (i) 1.0% by weight to 2.8% by weight of at least one copolymer (a) having at least one structural unit of formula (I) and at least one structural unit of formula (II) and at least one structural unit of formula (III), wherein R1 is hydrogen or a methyl group, X1 is oxygen or an NH group, and R2 and R3 independently represent a (C1 to C4) alkyl group, and (ii) 0.4% by weight to 1.4% by weight of at least one copolymer (b) having at least one structural unit of formula (I) and at least one structural unit of formula (II) and at least one structural unit of formula (IV), wherein R4 is hydrogen or a methyl group, X2 is oxygen or an NH group, and R5 and R6 independently represent a (C1 to C4) alkyl group.
