Bone Yard - G&P Complete i5 Version 2 Gearbox for M4/M16 Series Airsoft Guns (Store Display, Non-Working Or Refurbished Models)

"Very good gearbox for the price. Mine happened to work out of the box so no complaints there, but in the end it's a 40 dollar microswitch gearbox, so it doesn't get much better than that.

"Got one of these and these are a deal if you wana make any of your AEGs m4 style version 2, drop this in! The price of a nozzle, piston, piston head, spring, and more this thing just makes sense like others said it’s a 40$ mosfet system you might as well use it

"Picked this up as a boneyard gearbox for $39. Cleaned it, reshimmed it. Installed in an older G&P M4 from 2012. Works great. Fps is consistent with my particular barrel length. Great way to fix up my older M4 on a tight budget. If the proprietary mosfet dies, I'm not worried. $40 to "upgrade" and fix my backup rifle.

"This came in my G&P "Wirecutter" Carbine (https://www.evike.com/products/67221/) and I'm decently impressed with it. The biggest let-down is definitely the proprietary-nature of the mosfet.

"I’m happy with the gearbox itself, the stock shimming is nice and it fits well in a G&P reciever. I originally put this in a G&G upper/lower receiver, and it wouldn’t get good air compression no matyer what I tried to do. I then put it in a G&P upper/lower and it works well - but out of the box, the gearbox is slightly overspinning when I’m using a Krytac 30k high torque motor. If you really want to run a 30k motor, I suggest trying a high speed motor.