G&P Complete 8mm Reinforced Gear Box for M4 M16 Airsoft AEG
(Configuration: Rear Wired / For Deans / T-Plug Connector)

"Very happy with this gearbox. Put it in my completely stock G&G Combat Machine. It did require a little work to get it in. I could have used the thinner wires that came with the gun, but wanted to use the thicker and more flexible ones the gearbox came with.

FPS: I have had it chronoed with 0.20 bbs. Came in at 330 fps. I have another completely stock G&G Combat Machine that comes in consistently at 350, so this is a little slower... but MUCH quieter and smoother. The trigger response is infinity better even with the stock motor.

I plan on switching to an M120 spring and high torque high speed motor. That ought to get me closer to the 400 FPS limit of my local field.

"Got this for my g&g cm16. Dropped right in with a little snug fit. Had to do some wire splicing for the battery. The motor wiring is a little different so if you're doing this for your g&g then you'll also need a better torque motor and I'm investing in a more qualified handgrip too

"This is a very nice and high quality gearbox. I would though recommend re-shimming the gearbox and putting new silicone oil and teflon grease inside it. In my gearbox the bevel gear was not shimmed properly at all. I would also recommend switching the motor connectors to the more universal type motor connectors. It also comes preassembled and is packaged in a box with bubble wrap around it.