This is a BRAND NEW Goodman/Janitrol/Amana 2-Stage Gas Valve with part # 0151F00000PS (White Rodgers # 36G54 238). It has a 1/2" inlet and 1/2" outlet. Valve is 4" long.
The gas valve is a low voltage control (usually 24 VAC) that allow gas into the combustion chamber. It is also an adjustable regulator that insures proper gas pressure for combustion. They have a manual shut off.
36E54 246 36G54 238