Teledyne%u2019s hand-held GB300 Portable Percent Oxygen Analyzer is specially designed and developed for use in various applications from diving to fine tuning boilers. The light weigh and user friendly GB300 uses Teledyne%u2019s own micro-fuel cell sensor for rapid and accurate analysis of oxygen. The maintenance-free, sealed, electro-chemical cell is specific to oxygen, insensitive to flow rate, and offers 90% response in less than 10 seconds. The cell is discarded at the end of its life and replaced like a flashlight battery. GB300 is constructed of high impact resistant materials to ensure superior performance even in extreme environments. The unit is powered by 3 AA batteries that offer least 2000 hours of use.