Needles are as a rule; small and fragile. Consequently being prone to loss and breakage. The needle case does the job of containing and protecting them towards breakage and dulling. Needle cases can be made very elaborately or very simply, from wood, antler, ivory or bone. This one can only be classed as very simple and is made from sheep bone. When I get my hands on some reindeer (caribou) leg bone I will make a bigger, more beautifully carved version.
This design is of Inuit origin, but I know that other natives, including the Scandianavian Saami used similar designs. The idea is simple. You have a hollow case, a leather/buckskin strip and two stopping devices. When closed it looks like the photo below. The needles are then protected inside the tube.
To open it, simply pull the opposite stopping device.
The needles are stuck into a buckskin pad.
A proper belt hanger could be made for it, but for this one I used only a stick to make sure the thong doesn't go all the way through. I will just carry mine in a pouch.