This product has a bold design with elite functionality. Secondary regulators are used when you are attempting to dispense two or more kegs off of the same CO2 tank at different pressures. The secondary regulator has its own manual pressure release valve, internal pressure release valve that releases pressure at 55-65 PSI, and large pressure adjustment knob, and can be mounted to a wall or the inside of the keg refrigerator. In order to use this secondary regulator, you will still need a primary regulator with one output that connects to the secondary using a piece of the airline. The LHU5S-1 has a single 0.31" barb and a single gauge that indicates how much CO2 pressure is inside of the keg.