This banjo mandolin was made by the Bacon Banjo Co., Inc. in Groton, Connecticut around 1920-1922. It is a Banjo Mandolin Professional FF 3 model, serial #6896, with 20 brackets, 8 machine gear tuners. This instrument features the Bacon internal resonator design and Bacon's proprietary tone ring. This instrument features the following patent:

U. S. Patent #823985 dated June 19, 1906, by Frederick J. Bacon, for improvements in the construction of banjos.

Banjo mandolins are strung, tuned and played like regular mandolins, making it easy for players of the popular mandolin to add a banjo-like sound to their repertoire. The same idea also led to the creation of banjo ukuleles, banjo guitars and similar hybrid instruments. Advertising for these instruments was largely aimed at countless amateur banjo, mandolin and guitar clubs, ensembles, and vaudeville troupes which flourished from the late 19th century until the 1930s.