A coated or jacketed wire or cable, and components thereof are disclosed. When the vibration generated from the vibrating motor is transmitted to the associated mattress of the mattress set that is equipped with the vibrating motor, the unexpected vibration won’t occur in the other mattress sets because the mattress sets are spaced from each other, thereby enhancing the comfort of a user lying down on the mattresses. This cutting tool includes a holder and the cermet insert described above held and fixed by the holder. The random motion generator includes a hollow spherical shell.