This is a very handy DIN Scuba Tank/Cylinder Fill Checker! Features of this pressure check include: Quality fill checker Check Pressure of Standard DIN Outlet Valves Quick Bleed 2 Diameter - 0 to 5000 PSI Gauge & 0 - 350 BAR Accuracy 1.5% Throughout Entire Scale Triple Chrome Plating Protective Rubber Boot Model #OC100D Wonder no longer how much air you have in your tanks. Afford to dive with style. "