Made from uniquely refined co-polymer polyester with a soft molecular construction, Head Sonic Pro Edge string offers superior control and touch for extra pop and spin. This exceptionally durable string offers excellent response and playability that make a real difference. Made for perfect control, without sacrificing touch or feel. The pentagonal shape is excellent for players that hit with topspin or slice, giving extra bite to your shot and helping with placement. Head Tennis String 285513-16