The head graphene xt speed pro tennis racket endorsed by novak djokovic is the heaviest version in this tour range and offers good manoeuvrability and stability despite the heavier weight created for intermediate to advanced players the speed pro racquet delivers control and feel thanks in part to the 18x20 string pattern the racket uses heads latest graphene xt technology to strengthen the frame and distribute weight more efficiently to the tip and handle the racket swings very easily a