HM Digital Aquapro TDS Water Tester AP-1

Measures total dissolved solids (TDS) and temperature.
Automatic Temperature Compensation (ATC)
Water-resistant housing
Measurement Range: 0-5000 ppm
Digital Calibration (push button)
Auto-off function, data-hold function and low-battery indicator.
Display: large and easy-to-read LCD screen includes simultaneous temperature reading.
Factory Calibrated: The AquaPro is calibrated with a 342 ppm NaCl solution.
The meter can be recalibrated with digital calibration using the push buttons, rather than a screwdriver.
Includes a cap and batteries.
One year warranty.