niceeshop(TM) Echo Show Screen Protector Glass-2 Pack Wide Use: Ideal for household or laboratory use; Suitable for testing pH balance of drinking water, pool, aquarium, RO system, Spa, or hydroponics; Appropriate for wide range of applications Fast and Accurate: No need to work with color charts or messy test strips, this meter get the result fast and accurate. It with 0.01 resolution, 0.05 accuracy, full pH 0-14 measurements! Easy calibration: No need any adjustment screwdrivers, just press a button to finish the calibration. Automatic Temperature Compensation: ATC accounts for changes in temperature automatically LED display, read data clearly, even at night