Features： 1、Test the DO(dissolved oxygen) value and temperature(℃/℉) of water. Facilitate the user to carry on?site operation to display dissolved oxygen values and temperatures. 2、High accuracy and quick response, fast to get the testing result and can test the oxygen value for any 0.0?40.0mg/L liquid which you wanna test. 3、Pocket size, small pen shape design, lightweight and easy to move, you can test water anywhere to get the purest water. 4、With automatic temperature compensation function, the solution temperature can be automatically compensated 0?40℃, accurate and stable reading. 5、Suitable for freshwater aquaculture, mariculture, swimming pool, beverage factory, sewage treatment plant, laboratory, etc. Specification： Item Type: Dissolved Oxygen Meter Material: ABS Color: As shown in the picture Dissolved Oxygen Meter Size: Approx.155x35mm/6.1x1.38in Cable Length: Approx.1.15m/3.8ft Electrode Length: Approx.150mm/5.9in Weight: Approx.331g/11.7oz Measuring range: Dissolution: 0.0-40.0mg/L Dissolved Oxygen Saturation: 0.0-300.0% Temperature: 0.1-40.0℃; 32.0-104.0℉ Resolution: Dissolution: 0.1mg/L Dissolved oxygen saturation: 0.1% Temperature: 0.1℃; 0.1℉ Accuracy: Dissolution: ±1.5%F.S Dissolved Oxygen Saturation: ±1.5%F.S Temperature: ±0.5℃ Calibration Method: Support single-point or double-point automatic calibration, that is, null point or automatic 100% calibration in the air. Response Time: ≤45s (90% response at 20℃) Automatic Temperature Compensation Range: 0-40℃ Battery level: low battery warning Backlight: Not Supported Power supply: automatic shutdown for about 8 minutes Use Environment: 0.1-40.0℃ RH maximum 90% Battery: 3x1.5V LR44 battery 150MAH (Not included) Operating Environment: 0.1-40.0℃, RH maximum 90% Package List： 1 x Dissolved Oxygen Meter(Battery Not Included) 1 x Electrode 6 x Replaceable Electrode Head 1 x Instruction Manual