to answer a few of your question, CW threads, while it is a regular style m4 hop-up the hop up actually mounts into the gearbox and you do have to take apart the gearbox to remove it weather or not a standard m4 hop will work is unknown at the time. Some parts I am not to happy with is the piston and the piston head and those will be replaced they look and feel cheap and in a high fps setup will be destroyed, I will be changing the gears, adding a custom v2fix to the box, a metal piston head, the gun does not have a mosfet like ab style but the selector and switch is not a typical version 2 s