Small inner diameter is 5/16”Medium inner diameter is 3/8"Large inner diameter is 7/16” 0g and 00g are 1/2" diametere onlyCircles$40.00PriceGaugeSelectSizeSelectMetalSelectQuantity*Add to CartMost designs and sizes are available in: Stainless Steel (316LVM ASTM F-138) Brass (85% Copper/15% Zinc) Copper (straight up copper)