Feature: 1. Suitable for right- or left-handed golfers. 2. Easily attaches to the end of any standard golf club grip. 3. Projects a flat red laser beam during the swing to help visualize swing plane and identify positioning errors. 4. Supports swing posture improvement and enhances consistency and quality of each swing. 5. Simple and intuitive to use. Specification: Material: Metal Size: 8.5 x 1.9 cm (3.34 x 0.74 inches) approx. Package Includes: 1 x Golf Swing Corrector Plane Training Aid Product Usage: 1. Attach the device to the club grip. During the swing, observe the projected red laser line to assess swing plane alignment. 2. If the red beam points backward, the swing plane is too steep. If it points forward, the swing plane is too flat. When the beam points directly at the golf ball, the swing plane is optimal. Setup Steps: 1. Unscrew the battery compartment cover and insert one LR44 battery (battery not included). 2. Secure the cover tightly and mount the device onto the end of the club grip.