This is a funnel device for attaching to a multi-stage hand grinder. It allows you to easily regulate, and control the direction of flow of material out of the grinder. This particular design was made with the Sharpstone 2.2" herb grinder in mind: http://www.sharpstonegrinders.com/sharpstone-clear-top-4-piece-grinder-2-2-silver/I have had some success scaling it to fit grinders of slightly different brand/size. Let me know if you are able to make it work for other grinders. If you have the same size grinder as me then you don't need any scaling and should be able to print directly and start with step 1. If it is a different size scale it using 53.3mm as the base size of mine.