Disclosed is a thermoplastic composition including: a) 20 to 35 weight percent poly(decamethylene decanediamide), b) 50 to 65 weight percent poly(hexamethylene decanediamide), and c) 8 to 15 weight percent of sulfonamide plasticizer. wherein the sulfonamide plasticizer is one or more sulfonamides selected from the group consisting of N-butylbenzenesulfonamide, N-(2-hydroxypropyl)benzenesulfonamide, N-ethyl-o-toluenesulfonamide, N-ethyl-p-toluenesulfonamide, o-toluenesulfonamide, and p-toluenesulfonamideone.