Made from the same uniquely refined co-polymer polyester with a soft molecular construction as Sonic Pro, the new HEAD Sonic Pro Edge string now comes shaped for even more ball bite than before to offer more spin. This exceptionally durable string offers excellent response and playability that meet the demands of todays best players. Gauge: 16G or 17G Length: 40' / 12.2m Composition: Monofliament Copolymer Polyester Color: Black