Slinger Bag is programmable to a variety of settings, serve types and sequences, so you can keep it straight up lobs or challenge yourself with swerves and curves. Set your speed, anywhere from 10-80 MPH. Because some days you want to go easy on yourself but on others you want to be kept on your toes. Slinger Bag comes in an awesome tennis bag with space for your rackets, balls, towels, bottles, and is so modular you can even detach and use the tennis bag part separately. Made from high quality durable materials, Slinger Bag was made for the field. The inner mechanics are smaller updated versions of the ball launchers we all know and love, just with a few cool additions, like a charger for your phone.