This is a holder for unloading a drop spindle used for hand spinning. The two pieces are nearly identical, one has an enclosed retainer for the spinner end, the other a simple notch. I use one of each (see the photos), but print whichever works best for you! I use a piece of 1/4 inch rod as a spacer between them (you can use that, a dowel, pencil, etc.) and a couple of rubber bands to add some tension.