Class 4 microprobe

Class 4 microprobe was a type of sensor probe that was used by Starfleet in the late 24th century. The USS Voyager carried these microprobes.

When healing a spaceborne lifeform, Captain Kathryn Janeway of the Voyager ordered one of these microprobes launched, with the intention that it would act as a diversion as the lifeform was treated. The diversion worked.