Convertible gas regulator (made by Maxitrol) with integral vent tap, for use with natural gas (NG) or propane (LP) fuel. Comes preset for natural gas (4" W.C.) and is easily converted to propane (10" W.C.) by simply removing the seal cap and inverting/reversing the plunger then replacing the seal cap. Features 1/2" NPT inlet and outlet openings and a fuel flow directional arrow.  Rated 1/2 PSIG.  Overall length measures 2-7/8" and the square diaphram casing measures 2-1/4" X 2-1/4".