You know, maybe that is what this U100 number means. It means each cc is 1/100 of a ml. And maybe U1 would mean a cc is 1ml. I know there used to be U80 insulin syringes. And the cc units were different than the U100 ones. Today, I don't think you will find anything other than U100 syringes for insulin. It's pretty much standard nowadays worldwide.I'd doublecheck that. AFAIK, 1cc = 1mL, so 100cc = 100mL. A 1 cubic centimeter little open cube...will hold 1mL of liquid. Maybe you meant 1.00cc = 1mL...which would be correct.