The Sensus-Gas Division 143-1 is a natural gas meter designed to measure gas consumption in residential and light business applications. It has a conventional 1-inch inlet and outlet, and the gas flow is controlled by a 3/8-inch orifice plate. By keeping an eye on the gas pressure inside the meter, the green 6–14 inch WC pressure gauge helps guarantee reliable readings. https://www.partshnc.com/143-1-sensus-gas-division-1-std38-orifgreen-6-14-wc