Coaxial Waveguide Adapter, Type-N (f), 8.2 to 12.4 GHz
X281A - Keysight Technologies
The Keysight X281A adapter transforms waveguide transmission line into 50-ohm coaxial line. Power can transmitted in either direction, and each adapter covers the full frequency range of its waveguide band with SWR less than 1.3.