The Tac-Tic Knee Trainer is one of the most industry-changing training tools to come along in years. If you coach tennis, you know how many thousands of times each year you tell students the common instruction, “Bend your knees.” The Tac Tic Knee Trainer guides players to bend their knees automatically! They feel and hear a loud “click” exactly at the moment they bend, whether it is for general balance and movement, to load up before hitting a serve or groundstroke, or to get down for low balls and volleys. Simply put, if the Knee Trainer clicks at the right moment or remains clicked as needed, the right technique is in place. Includes detailed instruction sheet with guidelines to find those “right moments” to get you on track to better tennis.