This naked gauge has a 2-inch diameter with a 1.75-inch face. A Bourdon tube gauge, the Tech SPG is calibrated to 5000 PSI in 100 PSI increments (360 Bar in 10 Bar increments) for the highest level of accuracy. A tempered glass face is impact and scratch resistant, while the luminescent dial makes it easier to read in low light situations. Comes standard as a naked SPG with a spool to attach a hose swivel to the gauge. The Mini Tech SPG is suitable for oxygen service and is CE approved.