ATEC M1 Single Wheel Baseball Training Machine Compatible for use with regulation leather baseballs as well as dimple and foam machine baseballs Concave wheel treads increase ball grip and maximize pitch accuracy Dual durometer wheel hubs increase maximum pitch speed and minimize recovery time Quick Change Tilt System allows you to change the throwing hand and axis-of-rotation of pitched balls Durable steel frame and wide base tripod absorb machine recoil for maximum accuracy. ABS wheel guards help protect the operator and the machine wheels