Blowgun mouthpiece and darts.

thingiverse

Prints without supports easily with a 15% grid infill worked fine for me personally. Make sure not to aim at animals though. Scale it correctly by adjusting according to your tube size if different from 20mm (or 19.5mm Alfer). That aluminum tubing can be bought at any home improvement store you have nearby. Print the pieces upside down as instructed with no supports needed at all. To assemble them use a piece of aluminium tubing 120cm long max, preferably 19.5x1.5mm. Clean both ends thoroughly - inside and outside - then attach the mouthpiece using epoxy glue safely. Fill up those darts with water for extra weight and a neat little trail if you want to. And that's it, they're ready now!