The Unique Drill n Fill tennis trainer is a simple way to hone your strokes anywhere! When the ball bounces up, hit it while swinging your racquet from low to high. At first, do not hit the ball hard and straight out. Increase swing speed only after you have mastered to hit the ball back and forth at least 5 times. Let the ball bounce twice as it comes back to you. A nice complement to tennis lessons for learning the proper strokes for backhand and forehand. You will soon develop your rhythm and improve hand-eye coordination. Great for practice in your garage or driveway when a tennis court is not available. Strong rubber cord returns the ball. Can be used on clay courts just drive a spike into court and position handle over the spike.