This FAA Approved Rapco pressure regulator is designed to maintain a constant pressure at various altitudes and is used in aircraft with pressure instrument systems such as newer Beechcraft Bonanza. It is a direct replacement for the Airborne Model 2H30-9, and supersedes the 1H30-9. It is adjustable and come preset to 5.0 inches of mercury (HG). This model has a 5/8” hose inlet port and a 5/8” hose outlet port.