A method and apparatus for installing a wheel arm assembly for an autonomous vehicle. A roughened surface with a continuous pattern in a fine pyramidal shape is formed on a surface of a transparent substrate, the roughened surface is a diffraction surface with zeroth-order diffraction to visible light, and the pattern of the roughened surface is transferred from a mold at a transfer rate of not less than 70%. Another motor may be disposed near the wire source. The vibrating bars press against the underside of a vibrating screen to form a crown therein when the air mounts are inflated. The CPIR-enabling Servlets can be used to build various types of consumer product information systems for operation on the WWW. The device has an obstructing component that is mobile with respect to a plug and can be brought from an obstructing position to an unobstructing position in which the wrench can engage a rotor of a bolt when an identification code of the wrench, read by a reader, is in agreement with the code stored in an electronic module that is associated with the plug.