The two rackets in the Head Spark Pro squash racket double pack have frames stiffened by the Amplified Fibre technology (AFT) which gives the user more power. The Spark Pro has a 77.5in 2 (500cm 2) head & a frame that weighs 170g (6oz). Each of the racquets has a 12x 17 string pattern strung with a synthetic gut string & both come with a full protective cover.