High-Performance Rubber Combining Power And Stable Trajectory Grey Spring Sponge X is applied to Glayzer. Power, generated by spin, is brought to the stroke. Also, a stable trajectory is made possible thanks to the combination of a top sheet which possesses the ideal feeling of holding the ball, and the strengthened abrasion resistance of the surface adopting Spring Sponge X with a hardness at 38 degrees. Thus, this rubber provides players of wider ranging levels the joy to execute powerful top spin strokes from both forehand and backhand, focusing on spin and counter-attacking play.