Feature 1The product is suitable for right or left hand golfers. 2It is almost easy to connect to the end of any golf club grip. 3Give a flat red beam during the golf swing to check your swing position and correct the mistakes in time. 4Swing action, to achieve swing posture improvement, improve the quality of each swing ball. 5Easy to use. Material: metal Size: 8.5x1.9cm/3.34x0.74inch (Approx.) Package List 1 x Golf Swing Corrector Plane Training Aid Product usage and features: 1. Place the item on the handle and swing it to see the red line from the item, then check if the red line is in the right direction. 2. If the red beam is facing backwards, the swing posture is too high, and the red beam is facing forward, indicating that the swing posture is too low. If the red beam is facing the golf ball, the swing posture is correct. (pictured) Steps: 1. Unscrew the cover and place the LR44 battery (without battery). 2. Tighten the cover and put it into the end of the grip.