||Came in the mail today and it works perfectly, i have an a&k M249 para and the gears were destroyed after years of wear and tear. This pre-upgraded gearbox shoots around 390 FPS and around 17 bps with a 9.6v 2300 mah battery.
Pros: shoots Hard
Fits snug in my gun
Great trigger response
Cons: my fuse housing was cracked(fixed easy with some electrical tape)
The wiring wasnt quite long enough to wire to the front so I cut the zip tie and it was plenty long
A little more expensive than the average m249 gearbox
Has that nasty green gearlubish stuff in the gears, cleaned that out right away
Overall, 5/5 for this upgraded box. Brought my m249 back from the grave, I would recommend this.
Rating: [5 of 5 Stars!]