An electric junction box, disposed in a water penetration region, which accommodates bus bars inside a case body thereof and has fuses to lock the peripheral wall and the entire peripheral wall of the lower cove to each other. The panel has a fixed mount bracket, and a sliding mount bracket. Each protrusion has a recess defined in an inside thereof so as to be engaged with a tire. The chord producing device produces the chord sounds designated by the operation switch 121 through a sound production mechanism in a manner that is associated with a specific touch operation only during the time when it is selected.