-------------------------------------------------------------------------------- The Grand Slam Home Pitching Machine (HPM) is a revolutionary new batting machine designed to increase hand eye coordination. The idea for the Grand Slam HPM originated with the training acquired by some of baseball's greatest stars, like Babe Ruth and Willy Mays - stickball. Basically, the Grand Slam HPM has automated a time-tested activity that is guaranteed to increase hand eye coordination. The Grand Slam HPM utilizes a hollow plastic golf ball and 1" diameter bat creating a concentrated hit zone. This 2 ½" hit zone forces the batter to keep his/her eye on the ball - a key factor for any successful batter. Plus, the plastic golf balls are slightly irregular by design, which causes the pitches to be delivered randomly without any operator adjustment.