The application discloses a fire protection cover for an electrical device recessed into a wall or ceiling, said, comprising one or more support layers coated with one or more layers of intumescent material. The device is especially useful for suspended ceilings or partition walls for preventing the...http://www.google.com.tw/patents/US6226939?utm_source=gb-gplus-share專利 US6226939 - Downlighter cover
