New Manufacturer!   
Domed Disks - One pair (two disks) of approximately 2.5 inch diameter, borosilicate glass disks.  You can glue or solder the edges together with beads or colored objects inside.   There is a small hole in the center of each disk so that you can thread an axle for easy turning.  (the eyelets that come with the axle kit face outward, not inwards!).  Need an axle kit?   You can get one here for an extra charge of $3.00