HP 821676-001 webcam and microphone module is a replacement component for the display assembly of the HP EliteBook 820 G3 and 828 G3. The service guide identifies it as a webcam module with the microphone and cable included, combining these parts in one assembly.
The module is fitted at the display enclosure and connects through its cable. It is intended for servicing the built-in camera and microphone assembly when that component needs replacement. The service procedure treats the camera and microphone module as a removable part of the display assembly.