Bluelab TRUNV2 Truncheon Nutrient Meter, Conductivity Measure in SolutionQuickly monitor your nutrient level to maximize your grow and ensure plants get the balanced feed they need Measures (tds) EC, ppm 500, ppm 700 and CF with automatic temperature adjustments; no calibration required (comes factory calibrated) Fully waterproof and great for mixing a reservoir while measuring nutrients Other features: auto off function, no buttons or switches INCLUDES: AA batteries Made in New Zealand and manufactured by Bluelab, the