Etekcity Digital Handheld TDS Meter, 2% High Accuracy, 0-9990 ppm (Blue) Ideal for water TDS testing like aquariums, swimming pools, water filters, and more Measurement range of 0-9990ppm and 2% highly accurate and quick readings Data Hold Function: Freeze the tds meter measurement to view it out of the water Auto-off Function; Low power-consumption for years of reliable measurement Lightweight, handheld design; factory calibrated;CE/FCC/ROHS Approved; 2-Year warranty by Etekcity