The head graphene xt speed mp a is a high quality tennis racket that incorporates graphene technology into the shaft and frame to increase strength markedly whilst keeping the weight down the differentiating characteristic of this version of the graphene xt speed mp racket is that it comes supplied in a 1616 string pattern but it can be adapted to a 1619 pattern if desired the head light balance improves manoeuvrability and the racket swings well and transfers power to the ball more efficie