Tollan symbiote suppressor
From The Stargate Omnipedia
Advanced device of Tollan design capable of separating both consciousnesses of host and symbiote, giving each equal control of the body. A control device forces the symbiote to relinquish assertion to the host, whereas normally the symbiote maintains priority and control of who will speak.
A color indicator on the front of the device prevents one life form from masquerading as the other. Red indicates the assertion of a symbiote, blue, the host. The detachment device can be locked so that one is cut off from asserting itself until unlocked.
KEY EPISODE
Pretense - Skaara/Klorel is outfitted with a symbiote suppressor in order communicate with both and maintain proceedings for the Tollan triad.