Digital TDS-3 Meter Tester Thermometer Pen

This is a Digital TDS Meter Tester, for testing the purity of filter water, checking the performance of your water filter, and checking for hardness (1 grain = 17 ppm). Make sure you always drink pure water! Note: Do not drop the entire TDS meter into water or dip it beyond the maximum immersion level. This unit is not water-tight and is not covered under warranty if water enters the unit.