Features ACCURATE AND RELIABLE: For high accuracy, the water quality tester is equipped with an excellent Ti alloy probe that provide reliable automatic temperature compensation to ensure that the reading is always accurate at different temperatures. VERSATILE AND UPGRADED:Professional TDS, EC, pH, and temperature test pen 4 in 1. The large backlit LCD display has been upgraded to make it easier to read and the auto lock function is easier to use. HIGHLY SENSITIVE PROBE:Ti alloy probe and high sensitivity glass electrode, support high accuracy water quality measurement, can automatically warm, reduce errors. WIDE APPLICATION:Ideal for Home and Laboratory PH Testing, Including Drinking Water, Electroplating Liquid, Boiler Water, Water in Fish Tank, Water of Swimming Pools, Photograph Flushing Fluid, Well Water, Deep Phreatic Water, Aquaculture, Food Processing and More. POCKET PORTABLE:Small size but Suitable for testing pH balance of drinking water, pool, aquarium, RO system, Spa, or hydroponics. Specification: Item Type: Water Quality Tester Material: ABS Battery Model: 2 x Button battery LR44 Battery Capacity: 2 x 160mah Type of Measurement: TDS: Measuring Range: 1-9999ppm, Resolution: 1ppm, Accuracy: ±2% EC: Measuring Range: 1-9999μS/CM, Resolution: 1μS/Cm, Accuracy: ±2% PH: Measuring Range: 0.00-14.00pH, Resolution: 0.01pH, Accuracy: ±0.05 Operating Temperature: 0℃-60℃(32~140℉) Automatic Temperature Compensation: 0℃-60℃ Calibration: PH: Three point calibration; TDS or EC: One point calibration Package List: 1 x 4 in 1 Water Quality Tester 3 x PH Powder 1 x User Manual 1 x Storage Box Package List 1 x 4 in 1 Water Quality Tester 3 x PH Powder 1 x User Manual 1 x Storage Box