ABSTRACT: This is the user guide of the Maury Microwave WR28 Waveguide SSLT Calibration Kit for models WR28CK10\12 Series. The WR28CK10\12 series of waveguide SSLT calibration kits are designed to provide accurate calibrations of network analyzers in the WR28 band of 26.5 – 40.0 GHz. Each of these kits includes all the necessary SSLT calibration standards and associated hardware needed for the accurate calibration of most network analyzers.