Z.Vex Wah Probe
By the same people who made the Fuzz Factory, the Z.Vex Wah Probe is another pedal which has been integrated into one of Matthew Bellamy's guitars, specifically, the Manson 007. The Wah Probe is unique even in the Z.Vex pedal series in that it is a wah effect, which has a copper plate, instead of the usual footboard, and is controlled by hovering the foot above the pedal, the idea being, that there is no rocker pot to wear out. The recent Wah Probes also have a built-in Super Hard On, a boost/preamp pedal, with "Range", "Volume" and "Mix" controls.
In Matt's case, similar to the built-in Fuzz Factory, the circuitry is placed inside the guitar, with a customised copper plate mounted on top of the guitar body. The effect changes as Bellamy moves his hand over the copper plate.