For sale are two used  PARKER F800S FLOW CONTROL VALVES. The items are in very good condition.

I can include fittings if needed.

Flow Control Valve, Port 1/2-14 Inch NPTF, Flow Range 15 GPM (57 liter/minute), Maximum Pressure 5000 PSI (345 bar), Type 1/2 Inch Steel, Height 2.70 Inches, Length 3.44 Inches, Series F. 

This listing is for a Parker Flow Control Valve/CHECK VALVE 

Model: F800S

Metered flow 5000 PSI Max (345 Bar)

15 GPM (57 Liters/minute)

NPT: 1/2" FEMALE

Item is in Good Used condition