This is a BRAND NEW OEM Honeywell 24 volt Furance Smart Gas Valve.  The valve has an 3/4" inlet and a 3/4" outlet with two reducers that can reduce each end to 1/2" if needed.  The valve also comes with an LP Kit to convert the valve for LP gas if needed.  There are three wiring plug terminals on top.  Thanks for looking and good luck!

OEM Replacement for Old Part #s: SV9640M SV9640M3126 SV9540 SV9540M2245