A car wiper is a device used to remove rain and debris from a car's windscreen. A wiper generally consists of an arm, pivoting at one end and with a long rubber blade attached to the other. The blade is swung back and forth over the glass, pushing water from its surface. The speed is normally adjustable, with several continuous speeds and often one or more 'intermittent' settings. Inspection can be done regularly by lifting each wiper arm off the windscreen and run your finger along its rubber edge. If the rubber is rigid or chipped, replacement is needed.