Co-poly triangular shaped mains 17 gauge and co-poly round shaped crosses 18 gauge.
Take control of every shot, even the powerful topspin ones. The secret of the GRAVITY Hybrid String™ that sets it apart from the rest of the pack, lies within the unique combination of triangular main strings and round cross strings. Upon contact with the ball, the sharp edged main strings’ distinctive shape allows for maximum bite on the ball, while the round and thin shaped cross strings provide a fast snap back effect. The result: the ball rotates a lot faster so you get more of the winning combination of more spin and full trajectory control at the same time. In other words: Adding maximum spin to your game has never been under more control.
HEAD’s Crystal Core Technology is a unique string manufacturing process which utilizes a complex, multistep heat treatment of co-polyester strings.