Adopted by the Navy in 1926, the CSP488 was used for ship-to-ship and ship-to-shore communications, as well as communication between the Army, Navy and Marine Corps until is was declared obsolete in 1943. The device consists of 25 individual discs mounted on a central axis, with a threaded thumbscrew on one end. Each disc had a different sequence of the full alphabet, and numbered and lettered on one side. A "key word" was set for an operation or line of communication, which was used to set the wheels in proper order. To encode a message, the thumbscrew was loosened, and the plain text imputed by rotating the discs and lining up the letters on a brass guideline, then transmitting one of the resulting gibberish lines. This gibberish line is then entered the same way by the recipient, which will result in a plain English line if their Cipher is set to the proper "key word". Also with the cipher is the books "Military Cryptanalytics Volume I, Parts One and Two" by Friedman and Callimahos, and "Cryptography and Cryptanalysis Articles, Volume 1" edited by Friedman.

Excellent. All discs are present and accounted for, with no repeated discs. Books are very good.