SpecificationItem Type Hydrogen Test PenMaterial ABSH2 Range 0 to 2400ppb, 0 to 2.400ppmResolution 2ppb, 0.002ppmAccuracy 10ppb, 0.01ppmTemperature Range 0.1 to 60.0, 32.0 to 140Resolution 0.1/0.1Accuracy 0.5Working Environment 0 to 60 (32.0 to 140), RH 90%Waterproof IP67Battery 3 x 1.5V Button Battery (LR44) (Battery Not Included)Product Size Approx. 183 x 37mm / 7.2 x 1.5inDisplay LCD Digital Display with BacklitTemperature Automatic Temperature Compensation 0 to 60Data Retention Value RetentionAutomatic Shutdown 5 MinutesH2 Calibration Point 224, an Error of 20ppb is NormalApplication Suitable for Swimming Pool Experiments, Hydroponic Foods, Aquariums, Gardening, Laboratories, Water Purification Drinking Water, Pond, Etc.Weight Approx. 139g / 4.9ozPackage List1 x Hydrogen Test Pen (Battery Not Included)1 x User Manual