Single Flare > 12 gauge ~ 2.0mm > 10 gauge ~ 2.5mm > 4 gauge ~ 5mm > 1 gauge ~ 7mm > 0 gauge ~ 8mm > 3/4 inch ~ 19mm > 7/8 inch ~ 22mm > 1 inch ~ 25mm > 1-1/8 inch ~ 28.5mm > 1-7/8 inch ~ 48mm