Allows removal of the empty cylinder for refill without interrupting propane supply; includes 2 of the 12-inch pigtails to connect the regulator to the propane tank or propane supply For RVs with dual propane tanks; it automatically switches from primary to reserve tank when the primary tank is empty UL Listed Regulator, inlets are 1/4" SAE inverted flare and the outlet is 3/8" NPT female pipe thread; rated for 345,200 BTU Pairs well with our 48-inch thermoplastic hose; regulator is factory set at 11WC (water column) Double-stage design maintains constant gas pressure under changing demand and conditions