The GBC ChaosEgaddularRadulator, better known as the Emerald Radar, or simply Radar is a tracking device that Professor E. Gadd created. As the name implies, it shows the location of the Chaos Emeralds. It is first seen in Episode 4, created after E. Gadd used a Chaos Emerald to program it. It was stolen from the in the same episode by the Koopa Bros. During the battle in Episode 6, the Red Ninjakoopa lost the Radar and Sonic picked it up, and the heroes have been using it ever since. Following its theft, Professor E. Gadd created another Radar to hunt down the Radar itself.