AZ Waterproof EC pens raise the bar in ease of use, reliability, function and price, providing a large IP65 LCD screen with dual EC and temperature display. They have a wide measuring range from 0-9999ppm and a temperature range of -5 degrees to +60 degree Celsius. Another great feature is the waterproof IP65 keypad with simple calibration which also includes a hold button to freeze current readings in low visibility. ATC (auto temperature compensation) ensures accurate readings in all climates. Auto-off function maximises battery life.