In the films X-Men and X2: X-Men United, Cerebro is a massive device that fills a spherical room in the basement of Xavier's School. The helmet interface is similar to the version in the comics, although the bulk of Cerebro's machinery is contained in the surrounding walls. While in use, three-demensiononal images of the mind scanned by the device appear around the user. Unlike the comics' version of Cerebro, the film version can detect both human and mutant minds with ease. the Unique signature of mutant brainwaves is shown in the first film by having human mental images portrayed in black and white, while those of mutants show up in colour; In X2, mutants appear in red, and humans appear in white. The only person seen using Cerebro successfully in the films is Xavier; Jean Grey attempted to use the device, but the input overwhelmed her nascent telepathic power and left her stunned. It is mentioned that Magneto helped Charles Xavier design Cerebro. This has not been confirmed to be true in the comics, although the Magneto of the comics can use Cerebro and has designed similar devices. In X2: X-Men United, the device was copied and modified by William Stryker in his plot to use a brainwashed Xavier use his Cerebro-amplified power to kill the world's mutants, and was further modified by Magneto to kill humans. According to X2, it is difficult to pinpoint the location of mutants who have the ability to teleport and are constantly in transit, such as Nightcrawler.