Threat Sensor

"A reflected energy device [which] tunnels through walls to highlight obscured enemies."

― Equipment menu description

Multiplayer
The Threat Sensor is a device in DOOM that, when thrown, attaches to a surface and highlights enemies within its radius. Both allied and enemy players can hear it beep when they are nearby, and it can be destroyed with weapons fire. It is a multiplayer-only equipment item, and recharges after use. It's unknown why it takes so long to unlock (level 38) when it is basically just a weaker Threat Pulse. Thankfully, it does have at least one upside, which is that it can scan an area for far longer than a Threat Pulse.

Trivia

 * The image taken of the Threat Sensor says that its name is the 'UAC Threat Detector'.