1[Liquid Display] Large size backlit LCD screen is adopted, which has greater data reading angle and night reading ability 2[Safe and Reliable] Reliable water quality detector, accurate and fast, equipped with sensitive and high quality probes, the water quality detector can test quickly and conveniently 3[Accurate Display] Put the probe into the water and the LCD will display the accurate results in a few seconds 4[Automatic Temperature Compensation] Equipped with automatic temperature compensation, it can be adjusted according to water temperature and water quality to provide almost immediate PH reading 5[Scope of Application] An ideal water tester for water, swimming pool, aquarium, spa, hydroponics, food, wine and beer1 x Water Testing Pen(Shipped with Built in Battery)