Since its launch, the O2EII has been the preferred choice of divers for portable Nitrox analyzers. The new O2EII Pro is the latest version of this vital piece of scuba equipment. The O2EII Pro allows you to accurately measure your O2 percentage at the tank valve, or with the addition of the optional BCD inflator hose adapter, directly from your regulator while it is attached to your cylinder.
I always carry an analyzer on the boat with me to check my nitrox tanks, or for any last minute tank changes. Super reliable!