Description: 【Adjustable Magnetic Nut】: The badminton swing practice tool features an adjustable magnetic nut that allows you to control the suction of the slider, providing a customizable training experience. 【Instant Force Release】: When in a state of suction, an instant force release will cause the slider to and make a sound. This feature helps improve your swing speed and power. 【Material】: Badminton training device made from metal material, is designed for long time use and can withstand rigorous training sessions. 【Size】: The badminton training equipment measures 39.5cm in length, making it compact and easy to carry around for practice anywhere. Each package includes a badminton training device. 【Portable and Versatile】: Lightweight and easy to carry, this training device can be used anytime, and anywhere, both indoors and outdoors. You can easily bring this portable badminton trainer along at home, school, or on an outdoor court. Specification: Material: Alloy Size Chart: Length: 39.5cm/15.55inch Package Includes: 1 Badminton Training Device Note: Please allow slightly errors 1-2cm differences due to manual measurement.