King arms gearbox full set for m1a1 electrci gun

New full assembled model ready to install
comes with torque motor and motor cage
9mm steel ball bearing for amx torque and hi battery save

included parts:
complete gearbox case
wire and switch device
steel gears with 9mm ball bearing
metal spring guide with 1j spring
quality cilinder with seal nozzle
upper steel rail

for thompson type electric gun such Marui, ka, cyma and compatibles