Sports Tutor / Tennis Tutor offers some great features in their ball machines. Match Simulation is available on some models and lets you practice like its a match.
THE ENTRY LEVEL - FOR BEGINNERS.
Tennis Twist comes in battery or ac serves to about 15 mph and holds 28 balls. (weight is 11 lbs)
Tennis Cube - Basic AC and Battery. Weighs 20-28 lbs and serves ball up to 50 mph. Holds 70 balls and battery life is good for 1-2 hours. Also has oscillation model!
Tennis Tutor Prolite series - weighs 20-28 lbs, serves upto 60mph, 2-3 hour battery life and holds 125 balls.
Sports Tutor Tennis Tutor ProLite Battery Tennis Ball Machine - Smart Charger Included
DELUXE MODELS WITH ALL THE WHISTLES!
Tennis Tutor Plus with Heavy Duty Battery and 2- Function Remote
Tennis Tutor Plus Player Tennis Ball Machine with Multi-Function Remote