zippo

The cases of Zippo lighters are typically made of metal and are rectangular-shaped with a hinged top. Inside the case are the works of the lighter: the spring-toggle lever that keeps the top closed, the wick, windscreen, thumbwheel, and flint, all of which are mounted on an open-bottom metal box that is slightly smaller than the bottom of the outer case, and into which it slips snugly. The hollow part of the interior box encloses a rayon batt which is in contact with the wick. The fuel, a volatile flammable liquid commonly known as lighter fluid (usually naphtha), is poured into the batt, which traps it. It also contains a tube that holds a short, cylindrical flint. The tube has an interior spring and exterior cap-screw that keeps the flint in constant contact with the exterior thumb-wheel. Spinning this rough-surfaced wheel against flint results in a spark that ignites the fluid in the wick. The batt normally has a small hole to store spare flints. All parts of the lighter are replaceable. In all there are 22 parts, and the Zippo lighter requires 108 manufacturing operations.