BostonCraftWorks is the most comprehensive site on the internet for kaleidoscope kits and parts for hobbyists, artists, students and everyone else! Other crafts too!
We are going to add a full range of glass and acrylic disks. For now, we are adding what we have - some of these are in limited quantities for the time being. We will be adding more sizes soon. Here are the diameters of what we have currently: