Xiaomi TDS Tester Pen: Highly efficient and accurate due to its advanced microprocessor technology. Ease of Use: Open the cover and put the end of the pen into the water. Click, you can check and then know the TDS of the water in your home anytime. Design: Waterproof, low-power chips, detertable range 0-9990,0.0001 micron filtering accuracy. Advantages: Compact and lightweight, the fuselage about 30g, only a pen size, easy to carry, built-in two AG13 button battery can be replaced, convenient self-replacement. Auto-off Function: The meter shuts off automatically after 2 minutes of non-use to protect batteries and to extend the use of time.The product can accurate testing the purity of the water quality at home. It is simple to use, just single click, you can know the quality of water, convenient to use at home. Features Accurate testing the purity of the water quality at home. Simple to use, just single click, you can know the quality of water, convenient to use at home. Can test 3 kinds of impurities. Can test purity of the water quality at any time. Waterproof design, lower power procesor. Specifications: Brand: Xiaomi Color: White Battery: 2 * AG13 Material: PC Waterproof: IPX6 Item size: Approx. 15 * 1.6 * 1.6cm / 1.3 * 0.6 * 0.3in (L * W * H) Item weight: Approx. 3g / 0.1oz Package size: Approx. 17 * 5 * 2cm / 5.1 * 2.6 * 0.8in (L * W * H) Package weight: Approx. 88g / 0.98oz Package List: 1 * TDS Detection Pen 2 * AG13