Feature 1A water quality test pen that can measure four parameters: total dissolved solids (TDS), electrical conductivity (EC), salinity, and temperature. 2Not 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. 3With 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. 4High performance, portable human mechanical design, rapid measurement, high stability, good consistency. 5Compact size, lightweight, built-in temperature sensor, ATC (auto temperature compensation), intelligent function, high accuracy.Item Type: Water Quality TesterMaterial: ABSColor: As shown in the pictureSize: Approx.188x38mm/7.4x1.5inWeight: Approx.160g/5.6ozBattery: 3 x 1.5V button battery LR44 150MAH(Not included)Temperature Range: 0.1-60.0 32.0-140Temperature Accuracy: 0.5Temperature Resolution: 0.1/Working Environment: 0 to 60.0 (32.0-140); <90%Temperature Compensation: Automatic temperature compensation (ATC)TDS Factor: 0.5Salinity: Resolution: 0.01%Accuracy: 0.01-5.00% (0.1%) 5.10-25.00% (1%) .wang-edit-text{ font-family:'Arial' !important; } .wang-edit-text table { border-top: 1px solid #000; border-left: 1px solid #000; } .wang-edit-text table td, .wang-edit-text table th { border-bottom: 1px solid #000; border-right: 1px solid #000; padding: 3px 5px; } .wang-edit-text table th { text-align: center; }Package List1 x Water Quality Tester(Battery Not Included)1 x Instruction ManualNote1. 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.