Marshall Excelsior MEGR-9959P LP Regulator Marshall Excelsior Two-Stage Regulator, 9:00 Vent A high pressure regulator combined with a second stage regulator The MEGR-9950P reduces cylinder pressure to approximately 10 to 15 PSIG and then during the second stage completes the process by reducing inlet pressure down to 11 Inch of water column (0.4 PSIG) outlet pressure This innovative function results in a consistent inlet pressure to the second stage This product is required by RVIA (Recreational Vehicle Industry Association) as original equipment on your RV and should be maintained to the highest industry standards