The MEGR-253 Series Automatic Changeover regulators 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. Meets UL, RVIA and NFPA requirements. 1/4" Inv. Flare x 3/8" FPT. 225,000 BTU. Packaged.