The HP 85036E Calibration Kit is a precision RF calibration kit designed for accurate vector network analyzer (VNA) measurements using 3.5 mm connectors. Covering a frequency range from DC up to 26.5 GHz, the kit provides the essential calibration standards—typically including open, short, load, and thru—to perform full one-port and two-port calibrations. These standards allow engineers and technicians to remove systematic measurement errors such as mismatch, directivity, and tracking when testing RF and microwave components. Designed for use with compatible Hewlett-Packard and modern Keysight Technologies network analyzers, the 85036E helps ensure high measurement accuracy for applications such as RF component characterization, cable and connector testing, microwave device development, and laboratory calibration work. Rugged precision construction and a protective storage case make it well suited for professional RF labs, production testing, and research environments.