Dunlop blackstorm 4d tennis racket this dunlop blackstorm 4d tennis racket has been crafted with graphene xt technology which makes this racket lightweight and strong providing optimal weight distribution for a faster swing more power and an enhanced performance whilst the adaptive string system allows you to get more control and spin in your shots tennis racket graphene xt technology adaptive string system head size 645cm 100sq in weight 270g 95oz balance 340mm