Unit (IU on a syringe)

On a U-100 insulin syringe, one unit is 0.01 mL.

10 units is 0.1 mL, 50 units is 0.5 mL, 100 units is 1 mL. Units are a volume marking, not an amount of peptide, so the same 10 units can be very different doses depending on concentration.