These gauges are designed to fit into either our inline regulator or our blowtie units.  These can be used for water or gas.  
 
Specifications
Pressure: 0-30psi (0-2bar)
Graduations: PSI + Bar
Material: Brass/Plastic/Copper Capillary
Gauge Diameter: 20mm
Probe Diameter: 7.8mm (designed to fit 8mm hole)
Accuracy: These gauges are accurate to 10% of the whole pressure range.  (ie the 0-30psi Gauge is accurate to +/- 3psi).  For more accurate gauges we recommend the larger 50mm gauges that we sell.
 
WARNING:
Do not exceed gauge pressure.  If you exceed gauge pressure it will damage the capillary in the gauge and prevent the gauge from working correctly.  NEVER exceed the maximum gauge display pressure range.
Not tested or approved for pure oxygen.