Matrix G2 Complete Gearbox Assembly for TM Compatible V2 M4 / M16 Airsoft AEGs (Type: Rear Wire / 350 FPS)

"Awesome ROF and trigger response on this gearbox! I swapped out my worn out gearbox in my basic JG M4 and this made the rifle a hundred times better! I paired this with a high torque/speed motor and a 9.6 NIMH and it runs smooth.

"Bought this and dropped it in my first AeG , a lancer gen 2 19B.....Works flawless.....I'm going to buy another to drop in another door aeg of mine. Not Krytac quality but I've had zero issues so far...crisp trigger response, and an electronic trigger with a true quick change spring.....I recommend it

"Nice gear box I placed it in elite force stubby and it shoots about 430 fps making it my back up close quarters gun, I give 4 stars out of 5 because I don’t think it can handle a m160 spring just yet, I will order again as this gearbox out performs aps, elite force, it might handle a m150 spring maybe

"Having installed several of these, I can say that they are a good choice for a stock replacement gearbox. There isnt anything remarkable about this gearbox and it does have a proprietary trigger but having a built in mosfet at this price point is a good trade in my opinion. All internal parts are of the stock variety that you see in most out of the box guns. The mosfet works fine and the trigger response with an 11.1v lipo and a high torque motor is snappy and responsive. We have tested this gearbox with high speed motors as well as high rate springs and have had mosfet failures however. It is best that you go no higher than an M120 spring and use a motor that will fire at 20RPS or less with an 11.1v Lipo.

Pros

Built in Mosfet
QD Spring mount
Good trigger response (as tested)

Cons

Proprietary Trigger, selector plate and mosfet design.
Mosfet is only (in our opinion) designed for M120 Spring and stock type motors.
Replacement mosfets are VERY hard to find.

"Pretty good drop in gear box but one super important thing to know . The stock MOSFET has a sensor that is under the sector gear and is controlled for Semi Auto by a magnet that is on the stock gear. I did not know this when I was putting in SHS gears. Got the gearbox together to test it and would only fire full auto. What am I saying? Well if you plan to upgrade the gears either A) make sure the sector gear has a magnet on it, B) only upgrade the other two gears or C) buy/upgrade to a different Mosfet. It took a lot of troubleshooting before I figured this out. Hopefully I can save someone else some head scratching and heartache. Personally I wont keep the MOSFET considering the fact of the sector gear.
Overall stock it is okay for the money, came in on the chronoavg of 341 fps @ 1.38J. But if you plan to upgrade everything (sure you can keep the stock parts as backup) but probably just better to buy all the parts individually.