The Head Hawk tennis string has been developed in co-operation with Heads top pro players to deliver extraordinary energy efficiency ensured by the Head Crystal Core technology which helps generate explosive power without compromising on optimised control and touch in every shot. It provides more feel and power than a conventional polyester string and has a monofilament core for improved durability. The string is supplied as a 12m (40ft) set, which is enough to re-string one racket.