Personal cloaking device
From The Stargate Omnipedia
Technology making the wearer invisible. The user of this technology can be made visible with a T.E.R.
KEY EPISODES
Out of Mind - Hathor uses a personal cloaking device to hide from SG-1 when she captures them and recreates the S.G.C.
Fair Game - The System Lords learn that Nirrti possesses cloaking technology.
Rite of Passage - Nirrti returns using her cloak in attempt to remain undetected as she studies Cassandra's illness.
Metamorphosis - Nirrti uses her cloak to protect herself from Samantha Carter.