US oil barrels
A US oil barrel, also known as a petroleum barrel, is a volume unit used in the oil and gas industry to measure crude oil or liquid petroleum gas (LPG). One US oil barrel is 42 US gallons or about 159 liters.
Cubic Millimeters
Cubic millimeters are volume units in the metric system. A cubic millimeter is a unit of volume equal to the volume of a cube with sides measuring one millimeter each. It is a very small unit of volume commonly used to measure tiny amounts of liquids or solids. For example, a single drop of water may have a volume of approximately 50 cubic millimeters.