I have a not sure if its ever been used Global Manufactiuring Standard regulator flowbench with extra tank attachment. This is a special machine for testing all the important functions of scuba regulators and tank valves. They essentially embody the necessary compressed air source, hand tools, and instrumentation into a single aparatus designed specifically to repair / evaluate dive equipment. A Flowbench is made to actually simulate dives. The 48251 model is the Compact Deluxe Flowbench. This Flowbench retails for over $3600.00 new. I am selling this one for $2000.00. I aquired it when I bought out a divestore. It does not look like it has ever been used, and I have not used it but still I am selling it at quite the discounted rate. I will consider best offer on this item.