Feature: 1. A water quality test pen that can measure four parameters: total dissolved solids (TDS), electrical conductivity (EC), salinity, and temperature. 2. Not only detect the salt content of edible salt, salt water pool and koi fish pond, but also the salinity of seawater, marine, salt water fish tank salt level testing. 3. With backlight function, help you see the measurement results clearly in any situation, no need to worry about seeing the displayed value if the light is insufficient. 4. High performance, portable human mechanical design, rapid measurement, high stability, good consistency. 5. Compact size, lightweight, built-in temperature sensor, ATC (auto temperature compensation), intelligent function, high accuracy. Specification: Item Type: Water Quality Tester Material: ABS Color: As shown in the picture Size: Approx.188x38mm/7.4x1.5in Weight: Approx.160g/5.6oz Battery: 3 x 1.5V button battery LR44 150MAH(Not included) Temperature Range: 0.1-60.0℃ 32.0-140℉ Temperature Accuracy: ±0.5℃ Temperature Resolution: 0.1℃/℉ Working Environment: 0 to 60.0℃ (32.0-140℉); <90% Temperature Compensation: Automatic temperature compensation (ATC) TDS Factor: 0.5 Salinity: Resolution: 0.01% Accuracy: 0.01-5.00% (±0.1%) 5.10-25.00% (±1%) . Package List: 1 x Water Quality Tester(Battery Not Included)1 x Instruction Manual Note: 1. Please allow 1‑2in error due to manual measurement. Thanks for your understanding.2. Monitors are not calibrated same, item color displayed in photos may be showing slightly different from the real object. Please take the real one as standard.