Tracer orbs, also known as Eyes of the Master by Ygabba Hise and the other children under Gilramos Libkath's control, were tracking devices created by Gilramos Libkath. The orbs acted as miniature cameras, capable of sending detailed visual information back to Libkath. He installed them into his slaves so they wouldn't escape. If they did escape, the orbs would release a toxin into their blood stream and they would die. The orbs were installed by medical droids. The only way to deactivate the orbs was to ensure Gilramos Libkath's death.