This is a set of 17 rings from size 0 to 16. Each has the size of the ring inscribed into the ring. Print it yourself or get it printed for as low as $19.04 here http://shpws.me/3hka
added small which is 106x102mm platform which should be printable on smaller platforms.
1) Print or buy ( http://shpws.me/3hka )
2) try on until you find ring that fits
3) remember size of ring when ordering rings online.