Seemingly simple blow gun for Nerf darts is a challenge to print. Make sure you don't have any drafts in the rooms, and use modeling clay to support it after a few cm or so if needed. You can print as many as you need to get the length you desire. The longer the tube, the greater the accuracy and the longer the shot you can get. Assembles and disassembles quickly to fit in a pocket. Each tube is 150mm (around 6") long. The twists in the spiral vase offer two features. The first is that it acts as threads to keep the tubes tight together. Secondly, it also acts as a sort of rifling in the barrel to improve the accuracy. Should work with the majority of Nerf brand a clone darts. Enjoy!