WE-Tech Complete Full Metal Gearbox for M4 / M16 Series Airsoft AEG Rifles (Model: Rear Wiring)

"i fixed he issue with the anti reversal latch not releasing you need to dremil of file the front of the tooth and make it flat so it rest against the latch when running other whys it locks into the bevel gear to tightly i posted how to fix on youtube https://youtu.be/Aubh5PTBNJ4 original post is for the katana but the lower gearbox are almost identical

"Very nice gearbox, you cant beat the price with how high quality it is. I dont think its the normal 1:3 gear ratio because im using the same motor as my old gearbox and the rate of fire is now really fast. Re-shimming always recommended but I didnt re-shim mine, the factory shim job was flawless. If you buying this for a JG m4 ABS body, it is a very tight fit. the claw that connects to the anti reversal latch so when it goes in safety the latch disengages just jams up because the receiver body is not wide enough. You can file the inside if the body or simply take the claw off like I did, then shoot in semi once to decompress the piston spring. Nice job this gearbox is awesome for the price!

"Great gearbox for the price. Out of the package it was shimmed pretty nicely, though reshimming is always recommended. It is front wired and it doesn't come with a plug on the front of the wires so you will either have to buy one or use a spare one.

"So far so good. Out of the box it is a nice looking gearbox. Chrono'd over 400 in an M4 with a 363 inner barrel. I did have issues with the selector plate and the spring decompressing mech. Once i removed the ar latch mech and replaced the selector with a standard m4 one everything lined up correctly. I personally didnt like having to remove the tamiya connector everytime i took the upper off since it was front wired. So i cut off the pins and installed bullet connectors.

So far so good. Gearbox was shimmed well and very nicely built. Its only been a few weeks so only time will tell.