with high quality and good price. For checking TDS/salt (NaCl) levels in freshwater aquariums, ponds, and water purification systems. Smart pen combines TDS, EC, and temperature measurement for improved accuracy. Features automatic temperature compensation with a measuring range of 09999 ppm 2%. Four display modes: SHIFT button toggles between TDS - ppm & Celsius, EC - S/cm & Celsius, TDS - ppm & Fahrenheit, EC - S/cm & Fahrenheit. Hold function for easy reading and recording; press HOLD button then remove from test solution. Device automatically shuts down after 5 minutes of inactivity. Conductivity: 09999 S/cm TDS: 09999 ppm Temperature range: 0.180.0C / 32.0176.0F Resolution: TDS: 1 ppm; EC: 1 S/cm Battery: 1 x 3.0V (CR2032) Accuracy: 2% Color: White Material: Plastic Size: 152 x 30 x 14 mm Package Contents: 1 x TDS & EC Meter Only the above package content is included; other items are not part of the package. Note: Lighting and display differences may cause slight color variations between the image and the actual item. Measurement error allowed is 13 cm.