ARES Complete Gear Boxes Mid-Rear Wire w/ ECU for Ameoba / Ares M4 Series

ARES Complete Gear Boxes Mid-Rear Wire w/ ECU for Ameoba / Ares M4 Series Electronic control unit inside For you to alter the fire selecting mode (Semi / Burst, Burst / Full Auto, or Semi) Version 2 Gearbox (M4 AEG)