Generally these machines have a rechargeable battery which is very efficient, and removes the potential danger of having a power cord laying across the diamond.
Compressed air provides the force that propels each baseball or whiffle ball, and can send it reeling at either 25 to 65 miles per hour. Most affordable pitching machines will also double as a catching or outfielders practice run device as they will usually be able to throw over 125 feet high. With the optional external battery pack, capacity is doubled to over 1200 pitches, getting the whole team in good shape!