Check the listing for details. Estes 2240 Pro Series II Launch Controller for Launching Cluster Engine Rockets. Color: Brown/a, Condition: New. Listed at 43.99 USD. Great for launching cluster engine powered rockets! Fully assembled, just add your own 'C' batteries Features an alternative power source option for launching up to 10 rockets, a two-button arming and launch control system, audible continuity buzzer, and 30 feet (9.1 m) of heavy-duty cable with four alligator clips The ultimate launch controller for launching the new Pro Series II line of rockets as well as other mid engine power rockets! The Pro Series II Launch Controller is the ultimate launch controller for any single or clustered rocket! Powered by six, ‘C’ size alkaline batteries (not included), this launch controller provides plenty of energy to your single or two engine cluster rockets. The Pro Series II Launch Controller also features an alternative power source option for launching up to 10 rockets, a two-button arming and launch control system, audible continuity buzzer and 30 feet (9.1 m) of heavy-duty cable with four alligator clips.