Audible posture prompt: swing training is a built-in alarm device made of a special material that immediately generates a sound if you bend your elbow when swinging. You are warned that you do not have the correct posture; You must adjust your posture and keep your left arm straight. Usage: Thanks to the sound from our training aid, golfers can detect curvature errors in their left arm to keep the left arm in the correct position; therefore, an effective and desired stroke can gradually be formed; Suitable for all golfers or coaches, especially for beginners. A posture warning is issued: During use, a false posture warning sounds for the golfer when the elbow is bent. Then correct yourself to straighten your arm so that it can gradually achieve an effective stroke effect. Suitable for all golfers or coaches, especially suitable for beginners. Breathable material: our swing training aid consists of a high-quality, breathable nylon strap with closure. Is lightweight and does not put pressure on you. With a high degree of flexibility, you can easily insert your elbows into the cuff to create and maintain the correct distance between your left foot and right knee. NOT EASY TO CHANGE AND BETTER TO PREVENT: Compared to other suppliers who use a simple belt, our swing trainer sits around the entire elbow. Ours is not easy to move and it can better warn golfers.