Add-on guide to stabilize the filament tube above the feeder. Without the transparent tube is always sliding out of the feeder. The guide is mounted with the cable-clamp screw and the original tube is inserted through the guide.
To mount it correct you will need a little longer screw with a length from about 12mm.
Now have a look on version 2 with a wider plate to prevent bending of the guide... There is also no further need for the little black cable-clamp after mounting the guide on the rf1000!