For example: Agilent E4440A or Anritsu 68369
Keysight / Agilent YIG Oscillators (YTO)
Keysight / Agilent 5086-7500
Dual YIG Oscillator Assembly 2 - 20 GHz
Manufacturer: Keysight / Agilent
Keysight / Agilent 5086-7781
YIG Tuned Oscillator 3.0 GHz - 7.0 GHz
Manufacturer: Keysight / Agilent
Keysight / Agilent 5086-7786
Yig Tuned Oscillator Assembly, 3 - 6.8 GHz
Manufacturer: Keysight / Agilent