Mi-Wave’s 515 Series Direct-reading electronic Precision Attenuators
provide 0 to 70 dB of calibrated attenuation by rotation of a
resistive vane mounted in a circular waveguide section. These units are often referred to as ″precision rotary vane attenuators.
See more at
https://www.miwv.com/millimeter-wave-products/electronic-millimeter-wave-attenuator/
