Analox Oxygen Analyzer 02EII Pro for Scuba Divers Easy to use - Ergonomically designed comfort grip with automatic switch off after ten minutes. Easy to read - Once you have completed your analysis, simply freeze your reading on the display Easy to carry - The O2EII Pro is fitted with a handy wrist lanyard. Easy to maintain - The O2EII Pro oxygen sensor has a 4-5 year life span in air and is easy to change.