Merf 3.2?
http://www.airsoftstore.ca/index.php...roducts_id=135
Simple install gives 3rnd burst, ROF control, trigger arch protection.
Just by plugging in between the battery and gun.
Or you can wire it to the trigger for more fetures.
I have one i love it. Great service from airsoftstore as well.
They also have a cpl other fets