Cavagna (52-A-490-0008B Two-Stage Regulator Kit Cavagna Two-Stage Regulator Kit Horizontal Vent A combination regulator; first stage reduces cylinder outlet pressure to 10 psi, and the second stage maintains a stable working pressure of 11 inch water column Inlet: 1/4 inch Female Pipe Thread, Outlet: 3/8 inch Female Pipe Thread, horizontal vent, 160,000 BTU/hour Kit includes the plastic vent covers required by RVIA