HEAD Graphene 360 Speed X S Limited Edition Tennis Racquets : The Head Graphene 360 Speed X S tennis racquet was designed for fast-paced players who want a highly maneuverable, lightweight frame. This racquet utilizes Graphene 360 technology, which provides improved stability and energy transfer. The specified 16 x 19 string pattern allows for adding spin to shots for more varied gameplay. The Speed X S also features a limited-edition black-and-gold anniversary design that's sure to stand out on the court. Features excellent handling and power in a lightweight frame. Includes new Graphene 360 technology for more stability. Speed Series endorsed by Novak Djokovic and Sascha Zverev.