Feature:1. With automatic temperature compensation that will automatically compensate for the solution temperature of 0‑40 ℃, it can provide you with an accurate and stable reading.2. Suitable for freshwater culture, mariculture, swimming pool, beverage factory, wastewater treatment plant and laboratory.3. Compact pen-shape design, lightweight for mobility, you can test water anywhere to get the purest water.4. High accuracy and quick response: fast to get the testing result and can test the oxygen value for any 0.0‑ 20.0mg/L liquid which you wanna test.5. Adopts the digital screen display with backlight, which is more clear and convenient to read data.Specification:Condition: 100% Brand NewItem Type: Dissolved Oxygen Meter Material: PlasticMeasuring Range:Dissolved Oxygen: 0.0- 20.0mg/LTemperature: 0～40°CBasic Error:Dissolved Oxygen: ±0.3mg/L Temperature: ±1°C Residual Current: ≤ 0.15mg/LResponse Time: ≤30s (90% response at 20°C)Automatic Temperature Compensation Range: 0～40°CPower: 4 x LR44 Button Battery (not included).w-e-text table td,.w-e-text table th,;.w-e-text table,Package List:1 x Dissolved Oxygen Meter 1 x Electrode3 x Replaceable Electrode Head1 x Instruction1 x Plastic Box