A microdyne coupler is a device that could be used to delete information on a computer, leaving little or no trace.

In 2154, Lieutenant Reed used one of these to delete information stored in a data recorder which the crew of Enterprise had retrieved from the wreckage of a Rigelian freighter. Reed's attempt to erase the information was unsuccessful, leading Captain Archer to learn that the lieutenant was holding back important information from the Starfleet crew. (ENT: "Affliction")

In 2375, Crewman Kellin told Ezri Dax to get a microdyne coupler and recalibrate a transtator. (DS9: "The Siege of AR-558")