The Duramax Top badminton string from Wilson incorporates a highly elastic, Polyamide core to deliver excellent power & durability. It has a multifilament construction that ensures not only extra power, but also enhanced comfort making the string a preferred choice for players with arm problems. The Duramax is supplied as a 10m (33ft) long set with which you can re-string one racket & has a gauge of 21 (0.75mm).