Bluelab pH PenPlusThe Bluelab pH PenPlus is a handheld pH and temperature pen built around a replaceable probe, so when the probe wears you swap the probe rather than the whole pen. Built to IP68 standards, it is dustproof and waterproof for demanding daily use.Keep a spare probe on hand to minimize downtime and maintain confidence in every reading. A 30-day calibration reminder and double-junction probe keep measurements accurate and reliable.Available Options Measures pH and temperature (C or F) Replaceable double-junction pH and temperature probe IP68 dustproof and waterproof Includes pH 4.0 and pH 7.0 calibration and KCl storage sachets and guide Key Features Swap the probe, not the pen 30-day calibration reminder Compact, backlit, easy to read Ideal Applications Everyday handheld pH testing Hydroponic reservoir monitoring Growers who want minimal downtime