Pitching machines come in a variety of styles. However, the most popular machines are an arm action machine, circular wheel machine and a battery-powered compressed-air machines. The arm action machine simulates the delivery of a pitcher and carries a ball at the end of a bracket, much like a hand would. The arm action machine then delivers the ball in an overhand motion. The circular wheel machine contains one, two or three wheels that spin much like a bike tire. The wheels on these machines are usually set in either a horizontal or vertical fashion. With a circular machine, a ball shoots out towards the hitter after it is fed into the wheel or wheels. Three-wheel machines are more easily adjusted to be able to throw a variety of pitches and they can be used for a wide range of other practice scenarios, such as ground work or flyballs. Battery-powered compressed-air pitching machines, such as Zooka compress air in a barrel and release that compression to project a ball. These machines have additional safety features that wheeled and arm action machine's do not and are more portable. The use of pitching machines allows baseball and softball players the opportunity to get batting practice on their own. Most batting machines are set up in a
batting cage, a netted area that will contain the balls after they are hit. By using a pitching machine and a batting cage, hitters can get as much batting practice as they desire without necessitating the cooperation of a human pitcher (and without wearing out the arm of one willing to cooperate). The cost of pitching machines varies greatly. ==Use in Little League==