four matching fully functional salvaged chicago early 20th century rotating polished brass socket extension. the dual or double-sided brass shell socket was designed and fabricated by the benjamin electric co., chicago, ills. the fully functional socket has been lightly cleaned. the two painted glass light bulbs date to the 1930's and are in working condition. asking price includes theater cove light bulbs. multiple sockets available. socket extension with rotating sleeve and revolving hinge joint. the patented benjamin rotating dual socket cluster is most unique. the benjamin electric manufacturing company was a chicago, illinois electrical company was founded by reuben berkley benjamin in the late 19th century with its first filed 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 1920's. 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 1960's. in 1958, benjamin was bought out by thomas industries, inc. priced individually.