Specifications: Shell Material: Plastic Main Color: Yellow, Grey, Red as picture (Optional) Range: 0~9990ppm Accuracy: +/-2% Battery: 1.5v LR44 Battery: 2 x 1.5V LR44 Button Cell Batteries (not included) Size: Approx. 15.5 x 3 x 1.6cm / 6.1 x 1.1 x 0.6in Package Included: 1 x Water Quality Tester (without battery) Features: -The TDS meter tester can be used in: water purifiers and filters, food (vegetable, fruits) drink quality monitoring, pools and spas, aquariums, hydroponics etc. -Hold function: Saves measurements for convenient reading and recording. Auto-off function: Turns off meter after 10 minutes of non-use to conserve batteries. Press TEMP button can shift temperature meter between fahrenheit degree and centigrade degree. -Measures Range: 0-9990ppm, with a resolution of 1ppm. From 1,000 to 9,990ppm, the resolution is 10ppm, indicated by drinking x 10image, factory calibrated. Applicable industries: water laboratories, CDC, the aquaculture industry, hospitals, swimming pools, household tap water quality testing. Please refer below standard for testing water 0~50ppm --------- High Purity Water 50~100ppm --------- Pure Water 100~300ppm --------- General Pure Water 300~600ppm --------- The water will have incrustation scale 600~1000ppm --------- Bad Taste Water Above 1000ppm --------- The water is not suitable for drinking Note: 1. Please allow 0~1inch 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. Welcome to GS shop, hope you can have a nice shopping experience here ! ! !