The device was inserted into a subject through the back of the neck. It emitted a flashing red light. After this the subject could be controlled physically and mentally without being aware of the implant at all. Commander Kaagh used neural implants on Professor Skinner and his daughter Lucy, the latter to activate as a fallback plan if Sarah Jane tried to stop his plans. The device did not seem to require surgical insertion as the Professor and his daughter were both fine after Sarah Jane switched the implants off with her sonic lipstick. (TV: The Last Sontaran)
- During the Sontaran invasion of Earth during the same time period, other Sontarans used hypnosis without implants. Sarah Jane remarked that she was more familiar with Sontarans using hypnosis.