ABSTRACT: This is the user guide of the Maury Microwave WR51 Waveguide SSLT Calibration Kit for models WR51CK10\12 Series. The WR51CK10\12 series of waveguide SSLT calibration kits are designed to provide accurate calibrations of network analyzers in the WR51 band of 15.0 – 22.0 GHz. Each of these kits includes all the necessary SSLT calibration standards and associated hardware needed for the accurate calibration of most network analyzers.