The Conductivity Pen from Bluelab is a handheld EC and temperature meter built for growers who want quick insight into their nutrient solution. Designed with Automatic Temperature Compensation (ATC), such as the brand’s Truncheon Nutrient Meter and Pulse Multimedia EC/MC Meter, it delivers accurate measurements of electrical conductivity (EC) and temperature in one easy-to-read tool, helping you fine-tune nutrient strength for optimal plant growth. Ready to use straight out of the box, this pen has a bright backlit display and lets you measure in multiple units ( EC, ppm 500 (TDS), or ppm 700), while displaying °C or °F for temperature. Fully waterproof and floating in solution, it’s perfect for quick spot-checks in reservoirs, tanks, or hydroponic systems, which makes maintaining optimal nutrient environments fast, accurate, and fuss-free for growers of all levels.