"Harmonic pulse. Reads biodensity through pretty much anything."

The Harmonic Device is a piece of equipment in Call of Duty: Advanced Warfare used in the mission "Traffic". When four are placed, it creates a "window", allowing the player to see what's on the other side of a wall while still remaining unseen. The player can tag enemies and will also be able to see the heart rate of enemies. There were four enemies the player had to tag to save the hostages.