Fully functional, original tags, very clean. Mass flow controller for air by Brooks Instrument, model 5853 i Series. Flow: 0-300 SLPM Air @ 0°C, 1013.25 mBar. Gas: Air. I/O signal: 0-5 V. Power: 24 Vdc. P1/P2: 10/0 psig. 1500 psig max. Base is model 5863i. Pre-owned and tested industrial surplus from a closing plant in Quebec, Canada. Minor surface scratches only.