Tenergy 64 is a fast attacking version of the Tenergy Series. Spring Sponge is a totally new sponge created by Butterfly. The most notable feature is a sense of being able to hold the ball on the racket; this has been made possible by the innovative composition of the material used, which produces a spring loaded effect when contact is made with the ball. The result is that a player can control spin, speed and direction as required; the sponge will make you feel you are in total control. The pimples of Tenergy 64 have a thinner diameter than the pimples of Tenergy 05; they provide a softer feeling and more control on the ball.