For precise pH and Conductivity readings, utilize the HYDROS iV. This add-on ensures that the test sample is physically separated, preventing any electronic interference from other equipment in the aquarium system. This guarantees more reliable data by eliminating any potential issues. Made in the USA utilizing additive manufacturing techniques. iV Specifics Dimensions (LxWxH) : 4.5 x 3.5 x 7.5in (not including Probes and tubing) Available Holders: Two Probes and Four Acrylic Tubing Beaker size: 150ml Cord Length: 6ft Includes: Glass Beaker, Mixing Pill, and 500ml of Pre-Mixed kH Testing Reagent