Extech-DO600-Dissolved-Oxygen-Meter-EXTECH-DO600-p-Th-Extech-DO600-Dissolved-Oxygen-Meter-simultaneously-displays-dissolved-oxygen-&-temperature-Units-of-measure-are-saturation-mg-l-or-ppm-for-dissolved-oxygen-&-deg-C-or-deg-F-for-temperature-Advanced-features-include-Data-Hold-25-points-memory-auto-power-off-automatic-temperature-compensation-fully-watertight-IP67-salinity-&-altitude-compensation-This-meter-is-shipped-fully-tested-&-calibrated-&-with-proper-use-w