The product is convenient to use and simple to operate with high measurement precision and is suitable for environmental protection, waste water treatment, chemical laboratories, pharmacy, fermentation, chemical engineering, tap water and other fields. LED Display :three and a half digit display Measurement range: PH: 0PH-14PH mV: -415mV-415mV Resolution ratio: 0.01PH, 1mV PH measurement error: +/-0.1% The temprerature of the measured solution: 5-60 Temprerature compensation scope: 0-60 Automatic power-off time: 4 minutes Environment temperature: 0-40 Relative humidity: 85%RH (No condensation) Power supply: 3 AA batteries No vibration affecting performance in surrounding area. No gas in the surrounding air No other magnetic field interference except earth magnetic field Colour:As Shown Material:plastic Package Contents: 1 x Water quality meter(Due to different product batches, the appearance , which does not affect the use) Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.