1、Humanized design, LCD blue light display is more effective for eye protection. The electrode can be detached, and it is more convenient to replace the electrode. 2、Automatic shutdown function, the power will be automatically turned off after 8 minutes, which can save power without operation and last longer. 3、The portable salinity meter can be carried anywhere to measure water quality, such as tap water, RO system water, aquarium, mariculture, food inspection, etc. 4、Multifunctional tester, it has 5 kinds of functions including test TDS, EC, pH, salinity, and temperature of the liquids. 5、With automatic temperature compensation function, the measurement is more accurate. ABS materials is lightweight yet durable, easy to operate. Item Type: Water Quality Tester Material: ABS Color: As shown in the picture Size: Approx.188x38x38mm/7.4x1.5x1.5in Product Model: PH-3509 Measuring Range: PH: 0-14PH EC: 0-1999uS/cm 0-19.9mS/cm Salinity: 0-42% Temperature: 0-50℃ Resolution: PH: 0.1PH EC: 1μs/cm (<1999μs/cm) 10us/cm (>1999 us/cm) 0.1mS/cm TDS: 1ppm (<1999ppm) 10ppm (>1999ppm) 0.1ppt Salinity: 0.1% Temperature: 0.1℃ Accuracy: PH: ±0.1PH EC: ±2%F.S TDS: ±2%F.S Salinity: ±2%F.S Temperature: ±0.5℃ Compensation Temperature: 0℃-50℃ Power Supply: 3x1.5V AG13 (Not Included) pH Calibration: 2 points (4.01, 6.86) or 1 point (6.86) calibration (without calibration fluid) Automatic Shutdown: About 8 minutes 1 x Water Quality Tester(Battery Not Included) 1 x Screwdriver 1 x Instruction Manual