The Butterfly 401 shakehand racket is assembled with Butterfly Yuki rubber on both sides. The Yuki rubber is extremely tacky offering tremendous spin. The softer 2.1mm sponge layer will provide excellent speed and more 'springy' feel on all shots. Comes with a free racket cover.The Butterfly 401 shakehand racket is assembled with Butterfly Yuki rubber on both sides. The Yuki rubber is extremely tacky offering tremendous spin. The softer 2.1mm sponge layer will provide excellent speed and more 'springy' feel on all shots. Comes with a free racket cover.