I recently bought a filament dryer, which has small bowden tubes to feed the filament out. It was a pain, to feed these each time i swapped, so I made a end cap which holds the 1.75mm filament in the centre of it, whilst popping on the end of the Bowden tube sealing in any small access for moisture in the dryer. This allows for the filament to stay in the tube and slot in to a longer tube, which goes to the printer, the connectors allow for longer tube to connect to both ends.

Pull off the plug, and the filament is there waiting for you to slot in the tube to the printer.

Printed with 4mm Nozzle, 0.2 layers in PLA, due to the small parts i also added a brim to the model when printing for extra stability.

Depending on your printers tolerances, you may need to finely adjust the scale width to obtain a snug fit to your tubes.