The Heater Sports PowerAlley 60 MPH White Lite Baseballs (6 Pack) is your go-to for at-home practice. Lighter than a regulation baseball, these balls are more responsive to your bat for more lively play or more varied practice to sharpen your skills. Designed for outdoor play, these balls are compatible for use with the Sandlot Lite Pitching Machine at up to 40 miles per hour, or with any Heater Sports pitching machine at up to 80 miles per hour. The polyurethane fill is safe for use with any bat.