Fully functional, very clean, full specifications and manual included (45 pages PDF). Air flow sensor by Omron, model D6F-10A6-000. Up to 50 SLPM, flow rate 0-10 liters/min. Rc 1/4" flow ports. 3 pin connection (Vcc, Vout and GND). Connectors required are specified in manual provided. Pre-owned and tested industrial surplus from a closing plant in Quebec, Canada. Minor surface scratches only.