Zeepro Zim uses a proprietary cartridge system. In my experience, this cartridge design is prone to jamming, and is not easily refillable. This is the first attempt to address these issues by creating an accessory that allows bypassing the stock cartridge but still use the spool and base plate with the RFID tag. These two parts are designed to allow using the RFID plate without the cartridge top. This makes removing and replacing the spools easier, at the expense of having to reset the cartridge information each time a spool is replaced. It also allows the filament to unspool with less interference.Using this accessory requires disassembling the Zim cartridge. I recommend creating a new preset based on "Fast" with supportes disabled and "autofan" enabled. The supports are not needed for the small bridges involved with this design. Only the bottom RFID plate and the spool (minus the spool cover) will be used with these parts. The black o-ring around the filament can also be removed and set aside. The filament guide should site over the slot in the neck of the RFID plate, towards the bottom feed stepper. It is to ensure filament is guided into the stepper correctly. I have found that this piece is not really necessary, but can't hurt to ensure the feed is working smoothly. There is a slot in the top that is designed to accept a zip tie to hold this piece in place. A friction fit also works. Finally, there is a screw hole underneath for a 4-40 sized screw, if you want to hold this piece permanently to the base and provide more stiffness to the neck piece of the bottom plate. The larger back piece snaps on to the RFID plate and serves two purposes. First, there is a bit of a lip that holds the spool in place should it tangle and start to lift off the center pin. Second, it is designed to fit the clips in the back of the cartridge holder to provide tension holding down the bottom RFID plate, and spring tension on the neck against the bottom stepper pinion.