Displays TDS level of triple water line. Highly efficient and accurate due to its advanced microprocessor technology. Auto-Off function conserves battery power. The unit shuts off automatically after 10 minutes of non-use. Wide Range 0-9990 ppm (From 0 - 999 ppm the resolution is 1 ppm. From 1000 to 9990 ppm, the resolution is 10 ppm, indicated by a blinking 'x10' image.) Factory Calibrated:our meters are calibrated with a 342 ppm NaCl solution. Meters can be recalibrated with a mini-screwdriver. TRM1 Triple TDS Meter with three probes. Comes equipped with Mur-lok Quick-Connect T-fitting (1/4 inch standard, also available in 3/8inch or 1/2inch ). Installs quickly and easily. Specifications: Range:0-9990 ppm Accuracy:2% Conversion Factor:NaCl (avg. 0.5) Cable Length:24.5inch (including sensor) Fittings:1/4inch standard, also available with 3/8inch or 1/2inch Power source:2 x 1.5V button cell batteries (LR44 or equivalent; not included) Battery life:approx. 1000 hours of continuous use Tips: The product may be updated constantly ,Due To Different Batches, The Actual Product May Have Slight Differences Or Color Differences, Which Does Not Affect Use Colour:Photo Color Material:plastic Package Contents: 1 x Water Quality Purity Tester Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.