This is the Form of the Magic Ring, or rather Disc, of Solomon. It is to be held before the face of the exorcist to preserve him from the stinking sulphurous fumes and flaming breath of the Evil Spirits."

Ring Size Reference

Size 7 =Inner diameter 17mm = 53.4 mm Inner circumference
Size 8 =Inner diameter 18mm = 56.5 mm Inner circumference
Size 9 =Inner diameter 19mm = 59.7 mm Inner circumference
Size 10 =Inner diameter 20mm = 62.8 mm Inner circumference
size 11 =Inner diameter 21mm = 66 mm Inner circumference
size 12 =Inner diameter 22mm = 69 mm Inner circumference
size 13 =Inner diameter 23mm = 72.3 mm Inner circumference