Skin Eyelets > 10 gauge ~ 2.5mm > 8 gauge - 3mm > 6 gauge ~ 4mm > 4 gauge ~ 5mm > 0 gauge ~ 8mm > 1/2 inch ~ 12.5mm > 3/4 inch ~ 19mm > 7/8 inch ~ 22mm > 1-1/2 inch ~ 38mm > 1-7/8 inch ~ 48mm