The Head Hawk tennis string has been developed in co-operation with Head's top pro players to provide more power and feel when compared to a standard polyester string. It features the Head Crystal Core Technology that enables you to generate explosive power and offers improved durability ensured by a monofilament core. This quality tennis string combines energy efficiency with optimised control and touch in every shot. It has a gauge of 17 (1.25mm) and is supplied in a 200m (656ft) reel.