Microliters
Microliters are a unit of volume in the metric system used to measure very small amounts of liquid. One microliter is equal to one millionth of a liter. This tiny unit of measurement is often denoted by the symbol μL. To put it into perspective, a single drop of water is roughly equivalent to about 50 microliters.
UK gallons
A UK gallon is a unit of volume used in the United Kingdom for measuring liquids such as fuel and water. One UK gallon is about to 4.54609 liters or 0.16054 cubic feet making it substantially larger than the US gallon.