HM DIGITAL AP-3 Handheld TDS Meter Tester With Large LCD Screen Includes Testing For Hydroponics Gardening Aquariums Reefs Pools Spas Water Treatment Drinking Pure Filter system Specifications -Range: 0 - 9990 ppm (mg/L) -Resolution: 0-999: 1 ppm; 1000-9990: 10 ppm (indicated by a 'x10' icon) -Accuracy: +/- 3% -EC-to-TDS Conversion Factor: NaCl (avg. 0.5) -Power source: 2 x 1.5V button cell batteries (LR44 or equivalent) -Battery life: Approx. 1000 hours of usage -Dimensions: 15.5 x 3.1 x 2.3cm (6.1 x 1.25 x 1 inches)
