Features: Large LCD display, data hold, temperature unit switchable: / . Professional measurement for p-H/TDS/EC/SALT/TEMP/S.G/ORP/H2/Fertile/Resistivity. Suitable for household drinking water, hydroponics, lab, aquarium. With high sensitive glass probe, you can get a full measurement range of 0-14p-H. Probe is removable and replaceable, which extend service life of the water tester. Package Includes: 1x Water Quality Tester Specifications: Material: Plastic Size: approx 178x26mm/7x1in Type: standard/with backlight/single probe(optional) P-H: 0-14 TDS: 0-200000ppm EC: 0-200000/cm Salinity: 0-20% ORP negative potential: 1999MV H2 is rich in hydrogen: 0-2400 PPB S.G sea water specific gravity: 1.000-1.222 Temperature: 0-60 Nutrient solution fertility: 0-3 resistivity: 50 -20 note: Please allow 1-3cm error due to manual measurement. pls make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item.