A block molded from a polymeric material has a through passageway to contain a percussive shock wave. Springs may be secured to the inside surface or outside surface of the rings to allow the joint to bend in directions transverse to the axis of the springs. Because there is no leakage of electric current to an outer part of an external conductor of the coaxial cable, even when the connection of the connector and the coaxial cable to the antenna, distortion of the radiation pattern of the antenna is prevented. Meanwhile, a nonvolatile ROM cannot be configured as a high speedlarge capacity memory. A liquid crystal display dynamically receives a data stream from a computer where each of the displayed data values presents an optical characteristic to the filtered beam and causes diffraction into a plurality of diffracted beams, the character of which is dependent on the data displayed.