BIQU PC4-M10 Pneumatic Connector Fittings Bowden Tube Coupler Male Straight PTFE Tube Push for E3D-V6 Bowden Extruder Compatible with Ender-3 Ender-3 V2 3D Printers (Pack of 10pcs)

In case you're still waiting, these things always seem to be in stock :) I designed spool mounts for bearings and rods for my first set, then for the second set I just let the spools sit on giant desiccant pillows and they feed fine without the hassle. Throw in some $0.99 aliexpress hygrometer pucks to be extra fancy. PTFE tubing with an m3 screw in the end makes a perfect plug. The hygrometers read permanently bottomed out. https://www.amazon.com/dp/B0FJY5V1VF https://www.amazon.com/dp/B01IB81IHG