A clapperboard, also known as a dumb slate, clapboard, film clapper, film slate, bertolo clapz, movie slate, or production slate, is a device used in filmmaking, television production and video production to assist in synchronizing of picture and sound, and to designate and mark the various scenes and takes as they are filmed and audio-recorded. It is operated by the clapper loader. It is said to have been invented by Australian filmmaker F. W. Thring. Due to its ubiquity on film sets, the clapperboard is frequently featured in behind-the-scenes footage and films about filmmaking, and has become an enduring symbol of the film industry as a whole.