I have a Matrix G3 Micro-switch gearbox that i took out of the gun that i have listed on here (see my profiles page). It still *works* technically, the only thing is that it will fire for a while and then completely shuts off (like an auto shut off). I have carefully dissembled and reassembled the gearbox and there are no mechanical issues-- when it works, it fires as slick as whistle, but once it stops, it won't fire no matter what you do (until you disconnect the battery, reconnect, etc). So... It is a beautiful, wonderful box for someone who knows who to fix or wants a project/wants the bones. It is a great box, 8mm bushings, metal toothed piston, quick change spring system, etc etc. I have carefully reassembled and it "works" (until it locks you out). All components/screws/pieces are there. Wired to mini-Tamiya. Asking $50 shipped if purchased on here Message if you have questions