This is an easy-to-use instrument to test the water quality of drinking water, aquarium, swimming pool and so on. It adopts sensitive probe and can test TDS quickly and accurately. Mini size and light weight, it’s convenient and portable to carry with you anywhere. Note: 1. TDS is one of the indexes of water quality; you can’t just rely on it. 2. Size and color may be slightly different due to manual measurement and different light conditions. Thanks for understanding. Specifications: Model: TDS-M2/ TDS-M6 (Optional) Main Color: White Main Material: ABS TDS Measuring Range: 0-9990ppm Error: ±2%-3% Resolution: 1ppm Built-in Battery: TDS-M2: 2 * 1.5V LR44 Button Battery TDS-M6: 3V CR1225 Button Battery Item Size: TDS-M2: 134 * 25 * 14mm / 5.28 * 0.98 * 0.55in TDS-M6: 150 * 17 * 10.8mm / 5.91 * 0.67 * 0.43in Package Size: TDS-M2: 15 * 5 * 3cm / 5.91 * 1.97 * 1.18in TDS-M6: 17 * 3 * 2cm / 6.69 * 1.18 * 0.79in Package Weight: TDS-M2: 150g / 5.29oz TDS-M6: 25g / 0.88oz Package List: 1 * TDS