【3-in-1 Mode】: This pH meter features a 3-in-1 design, capable of testing the water quality of drinking water, aquariums, swimming pools, spas, spring water, and other liquids, ensuring safe drinking water for daily life. Please note: The pH meter in the video does not have a green backlight and is for reference only. Our pH meter has a green backlight. 【High-Precision Meter】: pH meter: Measurement range 0.00 to 14.00 pH; resolution ±0.01 pH; accuracy ±0.01 pH. TDS meter: Measurement range 0-19999 ppm; resolution 1 ppm; accuracy ±2%. Thermometer: Measurement range 0-60 °C/32-140 °F; resolution 0.1; accuracy ±0.5 °C. 【Powerful Functions】: This pH test pen automatically performs three-point calibration (accuracy 0.01 pH), eliminating the need for manual adjustment and making operation very simple. Additionally, it features automatic temperature compensation to help you obtain more accurate test values. It also automatically shuts off after 5 minutes of inactivity, extending the product's lifespan. [Wide Applications]: This pH meter is suitable for testing the pH value of various liquids, such as drinking water, aquaculture, aquariums, swimming pools, laboratories, schools, food, beverages, reverse osmosis systems, hydroponics, and spas. After use, wipe the device dry with a clean cloth. Keeping the device dry helps extend its lifespan.