ARES E.F.C.S. Metal Complete Mid-Rear Wire Gearbox Set for Ares (Ameoba) M4 AEG (One-Piece Cylinder)
Electronic Firing Control System (E.F.C.S)
Mid-Rear Wire Complete Gear Box Set Upgraded Version
Reinforced Metal Gear Box Housing
Reinforced full teeth piston, gearbox shell, and an upgraded EFCS which is ARES's MOSFET system
allow to shoot in either, Semi / Burst, Burst / Full Auto, or Semi / Semi as well.
Version 2 gearbox, will fit in MOST brand M4 AEG as all gearboxes are relatively the same shape and size
Some G&P and VFC bodies change depending on the model so there may be need for some modifications


*For you to alter the fire selecting mode, you will also need to purchase the ARES Electronic Firing Control System.