Brocks Instruments 5850E Mass Flow Controller Series E 20 SCFH 75′ F Gas: Argon. Unit was completely refurbished and recalibrated by Rosemount. It has not been used since. Please note: This part was reserved as a plant spare and as such the retail box may exhibit minor shelf wear. We do not use stock pictures in our listings, you are purchasing ONLY what you see pictured. Nothing more, nothing less. If you do not feel justified to leave 4 or 5 stars in EVERY category, please let us know first so that we can fix the problem. We appreciate your business! _gsrx_vers_612 GS 6.9.5 (612).