No Batteries or Power — Gravity and squeeze-activated filtration

Complete filtration system: Includes 28oz BPA-free bottle

Digital automatic calibration (one point)

add storage

Always calibrate after cleaning the probe or when readings seem inaccurate

GroLine 1413 µS/cm Conductivity Calibration Standard Sachets (25 x 20mL) made in usa water filter No Batteries or Power —HI70031G Premium 1413 S cm Conductivity Calibration Standard Professional grade conductivity solution designed for hydroponics, aquaponics, greenhouses, and laboratory applications. Single use sachets deliver convenience, accuracy, and portability for on the go testing. Key Features & Benefits NIST Traceable Accuracy: Standardized with potassium chloride NIST 2202 SRM in deionized water per ISO 3696 BS3978 Certificate of Analysis Included: Each lot