A convenient digital tool designed to quickly assess overall water quality. TDS (Total Dissolved Solids) refers to salts, metals, or minerals present in water. With the press of a button, this meter displays water purity in ppm (parts per million) on an easy-to-read LCD screen. Lower TDS levels indicate purer water, with pure water measuring 0 ppm. Ideal for testing tap water quality or determining when to replace a filter. (Note: This device does not test for biological contaminants.) Suitable for a wide range of applications including drinking water, water filtration and purification systems, hydroponics (nutrient testing), aquariums, DI systems, swimming pools, spas, and commercial or industrial use. Durable and portable, it includes a protective carrying case with a belt clip. Features advanced microprocessor technology and a built-in digital thermometer for accurate and efficient measurement readings. Measuring range: 0–9990 ppm Resolution: 1 ppm Accuracy: ±2% of reading Power supply: 2 x 1.5V (LR44 button battery, not included) Color: Black Material: Plastic Dimensions: 155mm Package includes: 1 x TDS Pen Other items shown in images are not included. Note: Lighting and display differences may cause slight color variation between the product image and actual item. Measurement tolerance: ±1–3cm.