Features 1??Backlight display, which enable you test water quality no matter at daytime or night time. 2??There is temperature compensation mode, suitable for a variety of scenarios. 3??Multi?function 7 in 1 more accurate measurement, hard plastic box protection, easy to carry. 4??Accurate measurement Hydrogen rich content in water, improve human sub?health. 5??Powered by 4pcs LR44 battery (not included), high sensitivity and accurate. Specification Condition: Item Type: Water Meter Material: Plastic Power Supply: 4pcs LR44 battery (not included) Description: ATC symbols appears in the lower left corner of the display screen, indicating that the instrument is in automatic temperature compensation mode. 1. When the measured value of hydrogen enrichment is greater than 2400 PPB (2.400 PPM), the overrange symbols will be displayed in the display area: '--'. 2. When the temperature is lower than 0?? or higher than 50??, the symbols 'L' and the symbols 'H' will be displayed in the temperature display area. Package List 1 x Water Meter 1 x Manual