If you want good place to buy active breaking mosfet setups or even an SW-Computer setup, go here >>>
http://extreme-fire.com
Here is a video that myself "Bad-Motha" and "MadMax" made of the SW-Computer from Extreme-Fire, used in an M4 w/ version 2 gearbox. This is not a stock AEG. This has had about $500 worth of upgrades all around, NO piece of this gun is stock. It's also using a 9.6v Mini Type Battery and powered by Systema Magnum series motor. PLEASE DO NOT USE the "SW-Computer" on any stock gun, unless it's a good, solid, high end brand.
YouTube - AEG SW-Computer by Extreme-Fire by Maks of SOG Airsoft
By the way I play airsoft in the USA. Check out my team @
http://www.sogairsoft.org