Filament Funnel Cap

Have you built dry boxes like this one, or this one, or any of the other multitudes out there that use a cereal box like this? More importantly, did it come with a funnel? Especially a funnel with a roughly 20mm inner diameter hole on the small end? Why bother drilling a hole into the cereal box that you can't plug, or printing an entire lid for the top, when you can just use that funnel to let your filament fly freely while keeping the spool as dry as a desert? Print this little cap out and you can let just the filament out nice and neat!Why not just use the funnel on its own? …why ask these questions? This funnel cap is designed to fit the cap of the narrow funnel that's typically used for pouring cereal that comes with a lot of the inexpensive plastic cereal boxes that are being used for filament dry boxes. It fits a standard PC4-M10 pneumatic connector if you want to hook a Bowden tube up t