Class-5 intelligence drone
A class-5 intelligence drone was a type of Federation sensor drone used for intelligence-gathering purposes.

In 2373, two such drones were stationed in the vicinity of Portas V. During his hunt for the Maquis defector, Michael Eddington, Captain Benjamin Sisko ordered that their sensor logs be retrieved in order to find out who had recently visited the planet. ()

Probes
Sensor technology