Bluelab Conductivity Pen is a fully waterproof and shock-resistant tool designed to measure nutrient (EC) levels and temperature in all kinds of solutions. With Automatic Temperature Compensation (ATC), it ensures consistent and accurate readings, regardless of temperature fluctuations. It helps you avoid over-diluting or over-concentrating your nutrient solution, maximizing plant health, preventing nutrient burn, and ensuring optimal yields. A must-have for testing and monitoring nutrient levels to provide balanced feeding for your plants.