Heartbeat Sensor

The  is an attachment used in Modern Warfare 2. The attachment allows the user to track multiple targets, much like UAV. The display screen can be folded out from the side of the weapon. It is first put to use in the level Cliffhanger, where Roach will find himself in near white-out conditions. The sensor can also tell the difference between friendlies and enemies. Friendlies are blue and enemies are white.