Features: Can measure PH/TDS/EC/ORP/SG/seawater specific gravity/temperature. The measuring range is large and wide, and can measure fresh water salinity and sea salt. This product detects the salinity of table salt. It can also detect the salinity of seawater. Food salinity measurement range: 0.00-25.00%, seawater salinity measurement range: 10.1-200.0ppt. IP67 is an international waterproof and dustproof certification. Prevent dust intrusion and short-term immersion. The portable TDS meter can be carried with you to measure the water quality of tap water, RO system water, aquarium, sea water, swimming pool water, etc. The automatic power-off function turns off the power after 5 minutes of no operation to save power. A fully transparent liquid crystal (LCD) is used to display 4-digit values and corresponding physical quantity units. Specifications: Model: C-600A (with backlight) / C-600 (optional) < EC: Measuring range: 0 to10000uS/cm 10.01-19.99ms 20.1-400mS/CM Resolution: 1 uS/cm; 0.1 mS/CM ; Accuracy: +/-2% of reading TDS: Measuring range: 0 to 1000ppm 1000ppm to 10000ppm 10.1 to 200.0ppt Resolution: 1ppm; ; 0.1ppt Accuracy: +/-2% of reading Salinity: Measuring range: 0.00 to 25.00% Resolution: 0.01% Accuracy: 0.01-5.00% (+/-0.1) %) 5.10-25.00% (+/-1%)PH: Measuring range: 0.01-14.00pH Resolution: 0.01pH Accuracy: + /-0.05pHORP: Measuring range: 0~+/-999mVSG: Measuring range: 1.000~1.222 Working environment: 0 to 60.0 degrees Celsius (32.0-140 degrees Fahrenheit); RH TDS coefficient: 0.4 to 1.0 Temperature range: 0.1- 60.0 degrees Celsius 32.0-140 degrees Fahrenheit Temperature accuracy: +/-0.5 degrees Celsius Temperature resolution: 0.1 degrees Celsius/degree F Power supply: 3x1.5LR44 (not included) Display size: 33*24mm Size: 183*37*37mm (7.2* 1.5*1.5in) Weight: 105g (3.2 oz) Packing list: 1 * 7 inches 1 meter 1 * English manual 3 * Buffer power 1. This item does not have a retail box 2. Precautions Be sure to clean the electrode after each use. 3. If the pH calibration cannot identify the solution, the electrode is damaged