High-accuracy and reliable pH sensor for lab, pool, hydroponics, etc. ,Sensorex S200CD Epoxy Body Bulb-Style Combination pH Electrodes, BNC Connector, Double Junction, 12mm Diameter, 150mm Length NO LONGER AVAILABLE AND HAS BEEN REPLACED BY SENSOREX MODEL pH2000 Virtually unbreakable with durable epoxy body construction and recessed protected pH glass Reliable and accurate over the full range of pH measurements (0-14 pH) No refilling or maintenance required with sealed gel-filled design Instantly ready for use and shipped in storage bottle for long shelf life One year limited warranty