Horizontal Drum Cast-iron Fill Gauge allows you to easily check liquid level of a horizontal drum at a glance no surprise re-orders or stock depletions. Use indoors or out. Sight gauge shows how much liquid remains in a 30 or 55-gallon (110L-200L) drum. Drum gauge installs easily by threading into a standard ” NPT bung hole and accepts any ” faucet. Rugged zinc-plated, cast-iron body stands up to heavy use. Heavy gauge glass tubing is protected with a chrome-plated housing and permits use with non-viscous oils. Buna-N seals make this unit ideal for petroleum product.