50 Gallon Lowboy Water Heater

water heater
Water heating is a thermodynamic process using an energy source to heat water above its initial temperature. Typical domestic uses of hot water are for cooking, cleaning, bathing, and space heating. In industry, both hot water and water heated to steam have many uses.
a heater and storage tank to supply heated water
An appliance for supplying hot water for purposes other than space heating or pool heating.

gallon
A unit of volume for liquid measure equal to four quarts, in particular
The Scots gallon was a Scottish unit of measurement of liquids that was in use from at least 1661, (possibly 15th century), until the mid 19th century. It was approximately three times larger than an Imperial gallon that was adopted in 1824.
Equivalent to 3.79 liters
The gallon is a measure of volume approximately equal to four litres. Historically it has had many different definitions, but there are three definitions in current use. In United States customary units there are the liquid (? 3.79 L) and the lesser used dry (? 4.4 L) gallons.
(also used for dry measure) Equivalent to 4.55 liters
United States liquid unit equal to 4 quarts or 3.785 liters

lowboy
A low chest or table with drawers and short legs
A lowboy (low loader in UK English) is a semi-trailer that has two drops in deck height; one drop right after the gooseneck and one drop right before the wheels. This allows the deck to be extremely low versus normal trailers.
a low chest or table with drawers and supported on four legs
A lowboy is a small table with one or two rows of drawers, so called in contradistinction to the tallboy or highboy chest of drawers.

50
This article lists firearm cartridges which have a bullet in the to caliber range.
fifty: being ten more than forty
fifty: the cardinal number that is the product of ten and five