This device is a portable digital water quality meter (TDS & EC Meter), primarily used for checking the purity of drinking water, home desalination plants, fish tanks, and hydroponics.💡 Main button functions: ON/OFF button: To turn the device on and off. SHIFT button: Allows you to switch between different measurement modes on the screen: Measuring TDS (Total Dissolved Solids) in ppm. Measuring EC (Electrical Conductivity) in μs/cm. Measuring temperature in Celsius (°C) or Fahrenheit (°F). HOLD button: Fixes the reading