The Tennis Tower was designed for home courts and facilities with available electric power. The Tennis Tower includes a full complement of standard features including 225 ball capacity, variable speed and variable height, built-in random oscillator, adjustable spin (except Competitor Classic), protective all-weather cover and 3-year warranty covering both parts and labor and extended warranties available. All Tennis Tower models include an elevation display so you can set it to your favorite spot before firing any balls. There are four Tennis Tower models available, which means you can select the combination of features that best meets your needs. The Tennis Tower Competitor Classic includes all the features above with the exception of spin. The Tennis Tower Competitor includes all the features above including spin. The Tennis Tower Club includes all the features above and includes a 2-button wireless remote control that lets you start and stop ball delivery, and control the side-to-side position of the ball throws. The Tennis Tower Professional Player in addition to all the standard features, and remote control, includes Player Mode. Player Mode simulates the shot patterns of real players. With the push of just one button, the Professional Player model (Patented) simulates a player on the other side of the net. Just push the Beginner, Intermediate, or Advanced buttons and the Professional Player model automatically picks an appropriate speed and spin and then changes both the side-to-side position and the depth of shots just like you were playing someone of that ability. The side-to-side position and depth of each shot is not simply changed in a random or sweeping motion but is computer programmed to simulate the shot patterns of real players. For instance, beginning players will see more shots towards the middle of the court and more variation in depth of shots than will advanced players. And you are not stuck with only the standard settings, you can customize the settings by adding or subtracting more speed, spin, or elevation as you like. The Professional Player model also includes a pre-programmed two-line function. At the touch of a button, the two-line function shoots balls to two preset positions. This helps an instructor work with two lines of students in a group lesson, or allows a single player to practice alternating forehand and backhand shots. There are actually two 2-line settings to select from, '2-line narrow' or '2-line wide', depending on your preference for spacing of the two positions.