[lurkingknight]

no such thing as a plug and play fet that you don't have to solder in. If you plug it inline with your battery it's not a mosfet. A mosfet is a relay that interrupts the trigger circuit so you're not sending unregulated full current through the contacts that cause arcing. Instead it uses a separate circuit to detect the trigger being pulled and on a main circuit that unleashes the full current to your motor.

Also without opening your gun to see where the original is placed otherwise it's hard to choose a replacement. If it's integrated into the gearbox like the ICS mp5 pro you are basically limited to the original factory one... but you won't know unless you open it up.

If you need to ask these questions, you really need to see your local gun doc. If you're feeling that adventurous, you'll have to open the gun up and find where the mosfet is placed or find pics of it taken apart.