Luxilon Alu Power is Luxilon's most popular string and the most popular string on the ATP and WTA tours (used by more than 50% of the Top 100 pros). Alu Power is a co-polymer composition, made using nylon, fluocarbon resin and aluminum fibers. The resulting string offers loads of control-oriented response along with great durability and spin potential. This string is 17L gauge which results in increased spin potential but decreased durability when compared to thicker gauges (16 for example).