Covert transmitters consist of electronic devices used to send surveillance information. A covert transmitter is generally built into low profile housings, or affixed to objects that arouse little to no attention.

Covert transmitters are used to gather conversations once they have been placed at the site of a target, be it a room or vehicle. Using a Covert Transmitter to broadcast a conversation means that the recipient of the covert transmission will need to use either a radio receiver or a recording device in order to hear the conversation.