Annic 3 in 1 Pocket Size Super Accurate Professional Tds, Ec and Temperature Meter Water Tester with Protective Leather Case 1. Perfect for testing drinking water, checking water filters, hydroponics, aquariums and much more. 2. The instrument with automatic temperature compensation function under measurement mode. 3. TDS tells you when you need to change your Filters... It Saves you Money and Protects Your Health 4. TECHNICAL SPECS: Accuracy:  2%. Range:0-5000ppm, 0-9990 s/cm, 0.1-80.0C, 32.0-176.0F. 5. Lifetime guarantee.