A mop wringer comprises a housing supporting a first roller and a second roller. The cutting segment comprises diamond punches which are melted into a binding material in such a way that they are embedded therein. The electro-optical element is for instance a liquid-crystalline display and the optical elements are for instance light-emitting diodes, which are used for backlighting the display. In an alternative embodiment, the luminescent material is incorporated into the composition of the wall structure during the molding process. Alternating layers of insulative material and conductive control gate material may be formed within the lined openings.