propane tank
A common type of gas cylinder designed to contain flammable gases like LPG (commonly propane and butane) generally intended for domestic/outdoor cooking and heating fuel. This tag should be used for the portable propane cylinders larger than portable stove fuel canisters, but smaller than the huge fixed pill-shaped tanks installed outside a building (example).
Propane tanks are identifiable by its stubby shape, the presence of a metal protective collar or neck ring around the valve at the top of the canister, a huge carry handle, and a metal foot ring on the bottom.