Siren #55 is a Model L Atwater Kent Radio Speaker Horn with a brown logo. The bell is about 14 inches in diameter. The base is made of reclaimed willow oak and walnut and finished with Betty’s Board Butter (beeswax & mineral oil).

In the late 1920s, Atwater Kent was the largest producer of radios in the world. Between 1923-1929, The Atwater Kent Manufacturing Company factory, at the corner of Wissahickon and Abbottsford Avenues in northwest Philadelphia, built radios, receiving sets, radio horn speakers, and other components. The factory consisted of two plants, the South Plant and the North Plant, that together covered more than 34 acres. The two plants were connected by an enclosed pedestrian bridge in 1929; that bridge was destroyed when the Roosevelt Extension was built.