Dissolved Oxygen Meter KMMW600 Range : 0.0 to 19.9 mg/ l O2 resolution : 0.1 mg/ l O2 Accuracy : ± 1.5% Full Scale Calibration : manual on 2 points ( zero and slope) Temperature Compensation : automatic, from 0 to 30° C Environment : 0 to 50° C / 32 to 122° F; max RH 95% Battery Type : 1 x 9V alkaline ( included) Battery Life : approx. 70 hours of continuous use Dimensions : 145 x 80 x 40 mm Weight : 220 g ( with battery)