Description: Improve Your Swing: This Tennis swing accelerator is designed to teach you how to swing like a professional player. It helps correct improper swing movements and master the right timing for exerting force, making it a great tool for warm ups and auxiliary trainingUnique Principle: The accelerator works by moving a slider in the middle of the racket up or down during your swing, creating a crisp sound at specific points of impact. This sound helps you judge whether your timing is accurate, promoting body coordination and whiplike swingsOvercome Common Problems: If you struggle with gripping your racket too tightly, having stiff arm and body during play, lacking speed and power, or not knowing how to lower the racket head properly, this tool can help. It's designed to teach you professional whiplike force techniquesForehand & Backhand Swings: Stay relaxed and coordinate your strength while controlling the timing of exerting force when using this accelerator. A loud impact sound will be heard when the slider reaches the top near the hitting area if done correctly; otherwise incorrect timing will result in ineffective power transferServing Practice: Achieve smooth serving actions with this training aid! No impact sound should be heard when lowering the racket head during service; instead, an impact should occur near the highest point of service when maximum speed is reached Specification: Material: PP, Metal Size Chart: Length: approx. 69 cm/27.17 inch Package Includes: 1Tennis swing accelerator Note: Please allow slightly errors 1-2cm differences due to manual measurement.