Filament tube feeders and tube holder for a filament spool dry box.
I used these connectors: https://www.amazon.com/Witbot-Straight-Pneumatic-Connector-Long-Distance/dp/B01KHN1HWY
The feeder was designed in Tinkercad so the resolution is not great (mesh triangles along curves). The holder is fine.
When the filament tubes are not in use the ends plug into the holder. You should be able to keep enough filament out of the end of the tube in the holder that you'll be able to pull filament through the tube later.
Can be used with or without the backs inside the box. The backs do help keep everything fully pressed and flat against the box walls though.
Attach to box with M3x16mm screws and (nyloc) nuts.
Push in connectors screw directly into the parts.
Use with 4mm OD PTFE tube.
Printed with 3D Solutech natural clear PLA
First Layer Nozzle: 215C Bed: 60C
Rest of print: Nozzle: 210C Bed: 60C
For the tube feeders I did a batch print with a 2mm brim and the parts close enough that all the brims printed together.