Tollan phase device
Device capable of giving any person or object armed with the instrument the ability to pass through any wall or barrier by temporarily pushing the molecules of the user's body out of phase with normal matter. The device is worn around the arm, and can be shared by more than one individual if they are in direct physical contact.
Because the user is not impeded by normal matter while the device is active, it allows for people -- or, in theory, weapons of attack -- to pass unimpeded through the iris protecting Earth's Stargate.
Enigma - Confined Tollan refugees use their phase devices to move freely in, out and through Cheyenne Mountain.
Pretense - Narim uses his phase device and sends Shroedinger the cat through the iris first to Earth to notify the S.G.C. a friend is coming, then comes through himself.
Between Two Fires - The phase device is instrumental in allowing Narim and SG-1 free access through many parts of Tollana structures in order to prevent the fall of Earth to the Goa'uld.