Triple Function TDS Meter for Water Testing in Home Lab Aquarium Pool with Digital Display 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:. 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.