FEATURES 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 The AquaPro is calibrated with a 342 ppm NaCl solutioncan be recalibrated with digital calibration using the push buttons, rather than a screwdriver Magnetic back Includes a cap and batteries