This RV Travelers Choice Propare Regulator automatically redirect LP gas vapor flow from an empty service cylinder to a reserve cylinder, without interruption of service. It features an easy to read green indicator which changes to red when the service cylinder needs to be refilled. As a two-stage high-pressure regulator, this reduces container pressure to approximately 10 to 15 PSIG and then the second stage completes the process by reducing inlet pressure down to 11 Inch of water column outlet pressure.