Microliters
A microliter (μL) is one millionth of a liter, the same volume as a cubic millimeter. A drop of water is roughly 50 microliters.
UK fluid ounces
A UK fluid ounce is about 28.41 milliliters, a little smaller than the US fluid ounce of about 29.57 milliliters. So 1 US fluid ounce is about 1.04 UK fluid ounces.