8-in-1 Digital Water Quality Tester Pen – PH/TDS/TEMP/ORP/EC/S. G/H₂/Salinity Monitor. ORP: ±1999 mV. Salinity: up to 20%. TDS: 0–100,000 ppm. A3: It is suitable for pool water, drinking water, seawater, aquarium water, and various industrial water sources.
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