It is a cost-effective and convenient digital tool that can instantly check your overall water quality. TDS means Total Dissolved Solids, which includes any salts, metals, or minerals present in water. With the push of a button, the TDS meter measures the concentration of dissolved solids and displays the result on the screen in ppm (parts per million). The lower the TDS reading, the purer the water, with pure water registering 0 ppm. This meter is ideal for testing tap water quality and determining when to replace water filters. (Note: The meter does not detect biological contaminants.) The TDS meter is suitable for a wide range of applications, including drinking water testing, water filtration and purification systems, hydroponics (nutrient testing), aquariums, deionized water, swimming pools, spas, commercial, and industrial uses. It features a rugged and durable design and comes with a protective carrying case. This handheld TDS meter is designed for reliable performance in various industries and is well-suited for commercial applications. The package includes a carrying case with a belt clip: advanced microprocessor technology and a built-in digital thermometer ensure accurate and efficient data measurement and retention for easy reading and recording. It features a clear and easy-to-read LCD screen. Digital TDS water testers are ideal for hydroponics, swimming pools and spas, aquariums and reef tanks, water ionizers, and general water quality testing. TDS meters are useful for testing drinking water, water purifiers, carbon filters, spring water, hard water, tap water, refrigerator water filters, reverse osmosis systems, and other water treatment applications. Measuring range: 09990 ppm, with 1 ppm resolution and 2% reading accuracy. Power supply: 2 x 1.5V (LR44 button batteries), not included. Color: Black Material: Plastic Size: 155mm Package Contents: 1 x TDS Pen Only the above package content is included; other items are not included. Note: Lighting and display differences may cause slight variations in the color of the item as seen on screen. Measurement error allowance is 13cm.