The MMU3 kit as of this moment is not available for upgrade and many of us want to get the unit off the shelf collecting dust, we need these files to be able to make the thing work. I could not buy the kit/ Tappex Microbarb. So I went into tinkercad and adjusted the files to support the 3 main ptfe fittings. For the one from prusa, you will have to thread it your self into the plastic. Hope this helps get these units off the shelf collecting dust and back into service.