- Star Trek: The Motion Picture
- Star Trek II: The Wrath of Khan
- Star Trek III: The Search for Spock
- Star Trek IV: The Voyage Home
- Star Trek V: The Final Frontier
- Star Trek VI: The Undiscovered Country
- Star Trek Generations
Starfleet-issue device inserted into the skin to enable the wearer of such a device to be tracked. In 2268, Dr. McCoy placed two such devices in Captain Kirk and Commander Spock before they beamed down to planet Ekos.