Has upgraded gears shs, piston shs, and cylinder shs it. It has a super snappy light trigger and it has a nice shim job. The gear box is pretty solid. The hop up is a classic army rotary style hop up and a tbb I don't remember the motor but it is 30k and rips rounds down range at about 28 rps. It has an M120 spring pushing 390 with .2’s