The National Cryptologic Museum added two very rare five-rotor Hebern cipher machines to its collection. The Hebern Electric Company built what is acknowledged to be the first five-rotor cipher machine in the 1920's (a number of others were designed independently about the same time). Although this machine was never widely manufactured or used, it is cryptologically significant as part of the overall evolution in U.S. manufactured rotor devices. We believe these two five-rotor machines are the only two that have survived. Financial assistance to acquire the Heberns came from an anonymous donor.