0 pins are on the high power RF circuit board.Input RF type Attenuator of the Evaluation board.Using the HMC812 search parameter, you can discover variants of the RF Board.PCB is the one that mounts RF Board.
123768-HMC812LC4 Features
0 pins Attenuator Type
123768-HMC812LC4 Applications
There are a lot of Analog Devices Inc. 123768-HMC812LC4 RF Boards applications.