Feature: 1. Adjustable Result: This water quality tensting pen can be conveniently switched between Celsius and Fahrenheit. 2. Multi Function: This water quality tensting pen display water quality TDS, conductivity EC and temperature values at the same time. 3. Data Retention: This water quality tensting pen possesses the function of data retention, providing more convenience. 4. LCD Screen: This water quality tensting pen adopts large LCD screen, which is very easy and clear to read the value. 5. Wide Application: This water quality tensting pen is suitable for tap water, household water purifier, commercial water purifier, industrial water treatment industry, etc. Specification: Item Type: TDS Meter Material: ABS Battery: 3V CR2032 x 1 (Battery Not Included) Uses: Tap Water, Household Water Purifier, Commercial Water Purifier, Industrial Water Treatment Industry, Etc Basic Parameters: Electrical Conductivity: 0-9999us/cm Celsius: 0.1-80.0℃ TDS: 0-9999 ppm Fahrenheit: 32.0 to 176.0℉. Package List: 1 x TDS Meter1 x User Manual1 x Cloth Bag Note: In general, the lower the TDS value, the less dissolved solids in the water, the purer the water. A higher TDS indicates more dissolved solids in the water, but it is impossible to tell if they are harmful.