15 in 1: This water quality test pen measures pH, salinity, temperature, TDS, and EC, offering multifunctional performance. IP67 Waterproof: Built with advanced production technology, this device is IP67 waterproof and can continue to function after accidental immersion, such as falling into a fish tank. Water Quality Meter: The multifunctional water quality tester features automatic calibration, replaceable probes, and a backlit display for easy reading. Measurable Salinity: Capable of measuring both sea salt and freshwater salt. Sea water salinity measurement range: 10.1–200.0 ppt. Freshwater salinity measurement range: 0.00–25.00%, with accuracy of ±0.01% for 0.01–5.00% and ±0.1% for 5.1–25.00%. Uses: Ideal for measuring various water quality parameters in drinking water, aquaculture, swimming pools, and similar applications. Specifications: Item Type: Digital Water Quality Meter Material: ABS Conductivity Test Range: 0 to 10000 µs/cm, 10.01–19.99 mS, 20.1–400 mS/cm Resolution: 1 µs/cm; 0.1 mS/cm Accuracy: ±2% of reading TDS Test Range: 0 to 10000 ppm, 10.1 to 200.0 ppt Resolution: 1 ppm, 0.1 ppt Accuracy: ±2% f.s of reading Salinity Measurement Range: 0.01% to 25.00% Resolution: 0.01% Accuracy: ±0.01–5.00% (±0.1%), 5.1–25.00% (±1%), ±2% f.s pH Test Range: 0.00–14.00 pH Resolution: 0.01 pH Accuracy: ±0.05 pH Temperature Compensation: Automatic Temperature Compensation (ATC) Working Environment: 0 to 60.0°C (32.0–140°F), RH 100% Temperature Range: 0–60.0°C (32.0–140°F) Temperature Accuracy: ±0.5°C Temperature Resolution: 1°C/1°F Automatic Shutdown: 5 minutes Battery: 3 x LR44 (not included) Waterproof Grade: IP67 Uses: Suitable for measuring water quality parameters in drinking water, aquaculture, swimming pools, and similar environments. Weight: Approx. 140g / 4.9 oz Package List: 1 x Digital Water Quality Meter 1 x User Manual 3 x Testing Powder