Cubic Millimeters
A cubic millimeter is the volume of a cube 1 millimeter on each side, so 1,000 of them make a cubic centimeter. It is the same as a microliter, and a drop of water is roughly 50 cubic millimeters.
US dry gallons
A US dry gallon is a unit of volume measurement normally used for dry goods such as grains, fruits, and vegetables. It is about 4.40488 liters or 0.16 cubic feet.
Note: The US dry gallon is different from the US liquid gallon, which is used for measuring liquids and is slightly smaller in volume.