The O2 stick is the first Diver Friendly oxygen analyser avaliable anywhere! Easy to use, effective, and affordable. The O2 stick is designed for the Nitrox diver who wants the convenience of having his own O2 analyser and doesn't want to pay a small fortune to own one. Operating the O2 stick is as simple as pointing at the tank valve and opening to allow gas to flow over the sensor. There are no switches to fail and the thermally compensated sensor maintains accuracy levels that exceed dive industry standards. The unit is totally O ring sealed for excellent water resistance.