Benjamin Electric Manufacturing Company was a Des Plaines, Illinois electrical company founded in the late 19th century. The company was founded by Reuben Berkley Benjamin and filed its first patent for an electric lamp socket in 1898. The company went on to manufacture various other electrical products. One of Benjamin's most notable products was their series of non-contact fire alarm horns, introduced in the early 1920s. They were available in flush-mount, single, and double projector versions, in either red or gray. These horns were mainly used by IBM, and later SimplexGrinnell up until the 1960s. In 1958, Benjamin was bought out by Thomas Industries, Inc.