Challenge: I have trouble extending their hitting arms to contact on their serves.

Solution: Click your way to better tennis! The Tac-Tic Elbow Trainer is an amazing kinesthetic aid that uses auditory feedback to help players improve faster. Simply put, if the Elbow Trainer clicks at the right moment, the right technique was used. A complete instruction guide accompanies the Elbow Trainer to help users find those “right moments” to get on track to better tennis. To use, simply place the device over your hitting elbow so the Tac Tic insert is midway over the elbow bone and straight up the back of the arm.