REDOX POTENTIAL(ORP) TESTER: ORP is a common, simple, and direct measurement that quickly indicate the degree of oxidation or reduction of water. By regularly monitoring ORP levels, effectiveness can be monitored and water treatment plans adjusted accordingly MULTI WATER POLLUTION TESTING: Portable TDS and EC meter can be carried anywhere to measure water quality, such as tap water, system water, aquarium, sea water and pool water PH METER: Temperature affect reading levels and the automatic temperature compensation of the water meter you get the most accurate reading possible DOUBLE SALINOMETER: The water quality tester detect the salinity of water. At the same time, the salinity of seawater can be measured. Food salinity measurements range from 0.0025.00%(you have never supervised your food) and seawater salinity measurements range from 10.1200.0ppt 7 IN 1 WATER QUALITY METER: Can measure PH, TDS, EC, ORP, S.G, salinity, temperature, the measuring range is and wide. Small and versatile, Perfect for home and laboratory pH testing applications including drinking water, swimming pools, beer brewing, kombucha, hydroponics, laboratories, food processing, and more size: about 18 x 4.5cm Material: ABS colour: blue Package Contents: 1 x Water Quality Monitor Tester Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.