The American inventor Edward Hebern (1869-1952) designed a series of machines for encrypting messages. The Smithsonian collections include a few of these as part of accession 1991.0190. Like many inventors, Hebern accumulated a variety of spare parts. These are some of them, part of museum transaction 1991.3033.
The four rotors are numbered on the rim "5"; "4"; "3" and "4". A steel disc is sandwiched between each plastic ring. Twenty-six cloth-covered wires pass through holes in the metal disc of each rotor and attach on each side. Three of rotors have lettered lugs at both ends of the wires.