Features: The hollows designs of the main body of the racket cover guides the wind, when resistance increases, the swing tracks will not move, and the swinging speed will raise. A tennis pointer is a great tool for tennis player training of any age, this tennis racket cover assists you to improve swing skills. The vibration generated when the balls hit the tennis racket resistance sleeve is also minimal, which can effectively decrease the probability of suffering from tennis elbow. Suitable for player, juniors, tennis coaches, and recreational player. Tennis training tool not only helps with the sweet Spots but also improves postures. Specifications: Materials: Flannelette Size: about 24x30cm/9.45x11.81inch Package Includes: 1Pc Tennis Racket Sweet Spots Trainer note: Please allow 1-2cm errors due to manual measurement, make surely that you not mind before order. Due to difference between different monitors, the picture may not reflect the actual color.