Heavy Duty: This indicates that the oxygen regulator is built to withstand the demands of heavy-duty industrial or medical applications. Heavy-duty regulators are typically designed for durability, reliability, and extended use.

CGA 540: This is a specification or standard that defines the type of connection used on the regulator. CGA 540 is a standard connection used for oxygen gas cylinders. It ensures compatibility between the regulator and the cylinder valve.

Oxygen Regulator: This is a type of gas regulator specifically designed for controlling the flow of oxygen gas from a cylinder to the desired application. Oxygen regulators are used in various settings, including medical facilities, industrial welding, and cutting processes.