For years, racquet designers at Head struggled with the same problem: They couldn't increase the power of their racquets without adding weight. The more weight a racquet has, the more momentum it generates during a swing and the more power it delivers to the ball. Too much weight, though, and a racquet becomes hard to control. The designers discovered that adding weight to the top of the head and the handle would make for a more balanced racquet. But with less weight in the middle, their prototypes kept cracking. So they looked to graphene, the world's strongest material by weight. By incorporating a small amount of graphene into the middle of the frame, designers improved its strength dramatically. The result is the YouTek Graphene Speed Pro, one of the first racquets to deliver both crushing power and precise control.