seldom found and exceptionally well-maintained original heavy ornamented cast iron wall-mount early commercial building or hotel elevator signaling system and/or annunciator designed and fabricated by knapp electrical works for the central electric company, chicago, il. the two-part hinged signaling device was commonly advertised as "the knapp" by a number of manufacturers during the 1880-1890's. the units varied in size, material and configuration. the most commonly found annunciator systems were typically used in residential settings and were comprised of a wood body or enclosure. the more commercial heavy duty plated-metal enclosures are much harder to come across. the built-in bell or ringer is original and intact. the glass pane protecting the black enameled panel containing the floor levels with their respective indicator arrows is surrounded by a nicely aged bronze metal border with a repeating egg & dart design motif. the mechanical components remain nicely preserved within the enclosure. the copper-plated iron exterior has been cleaned and sealed with a clear coat finish. measures 4 1/8 x 14 1/2 x 3 1/2 inches.