Tennis Tutor® is portable enough to take anywhere, yet powerful enough to challenge even top-level players. In fact, Tennis Tutor is used by tennis pros from the Association of Tennis Professionals (ATP). Tennis Tutor's patented technology, combined with over 20 years of experience and refinement, has made Tennis Tutor the #1 portable ball machine worldwide. Tennis Tutor features an electronic control panel which gives you fingertip control of ball speed, trajectory, and ball feed interval. Ball speed ranges from a gentle toss for children to world-class speed. Ball trajectory can be set anywhere between groundstroke and lob, while ball feed rate adjusts anywhere from 1-1/2 to 10 seconds. You can set Tennis Tutor to repeat shots you need to practice, or to oscillate and direct shots randomly across the court. Tennis Tutor also features an exclusive anti-jam ball feeding mechanism, and a 10-second start-up time delay to give you time to get to your side of the net. Tennis Tutor is truly portable, measuring only 12 inches tall when the ball hopper is folded down for transport. And with the towing handle extended, it tows just like luggage. When you get to the court, the ball hopper opens in seconds to hold 150 balls - more than two standard pick-up baskets full of balls. Tennis Tutor comes standard with a built-in heavy duty rechargeable battery that can deliver up to six hours of playing time, so there's little need for extra batteries. But if you do want more battery life there is an optional External Battery Pack. Tennis Tutor has a built-in battery charge indicator, and it even politely beeps when there is only one-half hour of battery charge left. And of course, Tennis Tutor comes complete with a Smart Battery Charger that fully charges the battery overnight. Tennis Tutor is backed by a three year warranty covering both parts and labor and extended warranties available. Popular options for the base model tennis tutor include Wireless 2-button remote control and 2-line function. The 2-button hand-held remote option lets you start and stop ball delivery, and control the side-to-side position of the ball throws. The 2-Line Function option automatically shoots to two preset court positions. This feature allows you to practice alternating forehand and backhand shots, or allows an instructor to automatically shoot to two lines of students. There are two 2-line settings, narrow and wide, for added versatility. All Tennis Tutor models can be ordered with AC power instead of battery power for a nominal additional charge. Optional accessories for Tennis Tutor Ball Machines include Smart/Fast Battery Chargers, External Battery Packs, Protective Covers and more.