This is a case for small knitting projects, like socks on DPNs (double pointed needles), with a separate screw-on cap. It protects the needles from breakage, keeps them from poking through your project bag, and keeps stitches from falling off the ends of the needles. It is sized for 15 cm long needles but could easily be scaled for longer or shorter needles if you prefer. You might have to scale by 10x because I am derpy at file unit sizes. The cap is a little bit tight when first used, but has enough clearance on the threads to screw on all the way once it's been put on and off a few times. Make sure to rotate the parts so that they print as shown in the picture with the two pieces separate (the base on its side with the slit facing up, cap with the hole facing up) for best printing results. Support is not necessary. A reasonable amount of infill and/or thick walls is advised as these are moving parts and thus need some strength.