Unlike any other machine, the Hack Attack Baseball Pitching Machine has a unique three-wheel design that allows you to see the ball clearly all the way through the feeding motion, acceleration and release, just like a live pitcher. The hitter sees when to stride and the angle of release, giving him an actual live-arm sense of timing and location. The three-wheel design changes the breaking pitch plane by simply adjusting wheel speed dials. (All two-wheel units require time consuming awkward throwing head adjustments to change from fastballs to curveballs or right to left handed breaking pitches.) With a quick turn of the dials you can effortlessly throw major league fastballs 100+ MPH, and right and left handed breaking pitches including curveballs, sliders and split fingers. The elevation adjustment handle will raise or lower the pitch. With a simple turn, you can even move the pitch up or down within the strike zone between pitches. (On other two-wheel pitching machines it may be necessary to release a locking mechanism, reposition the entire throwing head by tilting it manually and then re-locking the locking mechanism. These are awkward time-consuming adjustments.) Throwing head pivots instantly in any direction for all fungo work including deep 380 ft. fly balls that can drive fielders to the fence, slicing line drives, catcher"s pop-ups with reverse spin, towering infield pop-ups, and grounders. The Hack Attack quickly moves on and off the field, just tilt it, unsocket legs and easily roll on two transporting wheels. The front wheel guards insure the throwing wheels never come in contact with the ground. The Hack Attack is designed for use with regulation leather baseballs, dimpled practice balls, Wiffle balls and all softer practice balls. No assembly is required