According to The Golf Channel 

The swing plane is a crucial component of every golf swing.

Two hypothetical lines that extend from the ball over the player's shoulders and beneath their armpits might be conceptualized as the swing plane. Between these fictitious lines is the trajectory of an on-plane golf stroke. 

Golfers who do not swing "on plane" will never hit the ball with much force. 

This is incredibly hard to see, yet it is easy to grasp. It is practically impossible to see or feel where the club is throughout your backswing without pausing or looking up, but with this, you will always be able to see your swing plane and be able to FIX it right away. 

This compact and efficient golf training tool may be attached to any of your clubs and provides you with real-time feedback on the plane of your swing. Any club may readily accommodate the laser trainer. 

It serves as a training tool for your driver, irons, and wedges all at once because it works with any club. Men, women, kids, seniors, left-handed, and right-handed golfers can all use it! 

To measure your swing plane, all you have to do is locate or draw a target line. Alignment sticks are effective. 

Check during your follow-through, backswing, and downswing as you practice your swing until the laser remains parallel to the target line. 

By practicing with your own clubs, you may quickly enhance your golf swing and transfer your training to the course. With a little practice with our laser golf swing plane trainer, you will build muscle memory. 

Receive Immediate Visual Feedback Regarding Your Swing 

• ✓ Easy to use, compact, and compatible with ANY CLUB, making it portable. Men, women, kids, seniors, left-handed, and right-handed golfers can all use it! 
• ✓ An excellent indoor and outdoor golf swing training. One of the greatest tools for improving swing plane in golf training
• Enhance Your Skills! Lower scores will result from using the golf swing trainer to help you swing in the PROPER SWING PLANE.
• Batteries are included. Simply open and begin training.
• ✓ With the help of this laser golf swing trainer, you may start hitting the ball with accuracy and consistency right away. 

How to Use It:

1. Attach the laser pointer to the grip by rotating screws.

2. To measure your swing plane, all you have to do is locate or draw a target line. Alignment sticks are more effective.

3. Check your swing during the backswing, downswing, and follow-through to make sure the laser remains parallel to the target line.

4. By practicing with your own clubs, you may quickly enhance your golf swing and transfer your training to the course. With a little repetition with this laser golf swing plane trainer, you will build muscle memory. 

Details:

• ✓ Dimensions: 60 x 13.5 mm
• ✓ Type: Trainer Swing
• ✓ Suitable for: Beginners, Left and Right Hand Golfers
• ✓ Battery Operated Derivative Series
• ✓ Weight: 29 grams 

Contains:

• One Laser Swing Aid for Golf
• — Three Lr44 button batteries (sometimes called Ag13) are included.