This is an Agilent Keysight U8481A USB Power Sensor.  This unit is in GREAT condition and guaranteed fully operational.  I have TWO of these, one per bid.

U8480 Series USB thermocouple power sensors come with a measurement speed of 900 readings/second and power linearity of less than 0.8%, providing high accuracy and stability to help you make average power measurements quickly and confidently. With the U8480 Series USB sensors, one of the most cost-effective solutions in Keysight's power meter and sensor portfolio, you get top performance features at costs so affordable that every engineer can carry one in their bags.
  • Frequency range 10 MHz to 18 GHz
  • Fastest measurement speed for thermocouple sensor, > 400 readings/s (free run/fast buffer mode)
  • Best-in-class power linearity of less than 0.8%
  • Wide dynamic range from -35 dBm to +20 dBm

Shipping in the USA is $30.