[Application]: Through Tik-tok sound to warn their incorrect posture to golfers, and then correct by self to make arm in straigh, therefore it can gradually form effective and desired hitting; Fit all golfers or instruction, especially works great for beginners [Tik-Tok Sound Prompt Incorrect Posture]: Built-in alarm device which made of special material makes a Tik-Tok sound immediately if you bend your elbow when swings ; It prompt you that you are not in correct posture, you should adjust posture and keep left arm on straight [Adjustable and Easy to Wear]: Strong and buckle make it adjustable, easier to put on and take off; The thick plastic buckle will not scratch your skin; It fits for people whose elbow circumference is below 33cm [Non-Slip and Better Warning]: Our training aid swing can be worn around the entire elbow, not easy to move and meanwhile give a warning if your arm is bend [Breathable Fabric]: This training aid swing is made of quality nylon breathable cloth, webbing and closure, and lightweight, never give much pressure to your elbow