These gauges were developed by Aeronautical Data Systems Inc. In addition to displaying cylinder pressure, it will also display % of full, liters remaining and most importantly will calculate Time remaining. It will also calculate the flow rate of the gas.
There are 15 new gauges left. The fixed sale price is $219/gauge of if someone buys the entire lot then $350/gauge or best offer. The gauges can be programmed for a certain gas. Currently they will be set for either oxygen or nitrogen. These are the only gauges in existence that provide all of these metrics.