King Arms Version 2 8mm Gearbox with Quick Change Spring Guide

"solid construction but the measurements were a bit off. i had to shave down my cylinder just a tiny bit to close the gearbox fully and hammer in the little circle pieces that the 3 rotating gears connects to.

"After doing a complete build of this gearbox there are many things to make note.

You will need some tech experience, dremel and patience to work with this gearbox if your not working with Kings Arms parts

1. If you plan to use the Krytac Flat trigger you will need to dremel the gearbox.

2. If you plan to use a Gate Aster with the Krytac Flat Trigger, you'll need to dremel the gearbox.

3. This gearbox does not work with a Lonex M120 spring. It binds you and Jams the piston thus not firing.

5. The barings are a little tough to install, pay close attention to them. If you dont, your gears wont turn freely.

6. Some pistons might be too large for this. I found a piston with a size (measure from the guides on each side) of 21.14mm or less to work. Others will be too big and not slide.

7. Your safely latch will probably need to be sanded down (if it's not a Kings Arms brand).

Aside from those, I did find this gearbox fit into my Bolt AEG so that was a plus.