A Synaptic Nerve Suppressor was a device present on Earth after the Taelons arrived on the planet. It was an electronic device designed to help users relieve waves of pain and were able to be adjusted to cope with the pain. Further adjustments allowed a user to wield it as a weapon that generated powerful electromagnetic pulses that were believed to be capable of killing even Taelons.
Shelly George was equipped with a Suppressor after her exposure to a Taelon probe which she had to regularly adjust to cope with the pain. She later used it as a weapon when she took Synod leader Zo'or hostage on her teleivison show. George used waves of energy from the device to kill Volunteers until Liam Kincaid used a Taelon shuttle crash pack to create protector bull that disintegrates Shelly. (Episode: Interview)