Also known as Jefferson disk, Bazeries Cylinder, and more recently the M-94.
Although Leon Battista Alberti had invented the "Alberti cipher disk" a practical cylindrical implementation of Alberti's method was unknown until the Jefferson Disk later used by the US Army as the M-94.
The great advantage of the wheel cipher is it is so simple to use, provided encoder and decoder have identical wheels and have agreed on their sequence.
To encrypt write down amount and the order of disks (represented by the random seed number) and rotate the rings to spell out your message. Next choose any row above or below the cleartext, this row becomes your ciphertext. If you run out of wheels while encoding simply start over at the beginning.
To decrypt organize the disks in the same order, and position them so they spell out the cipher text. Then check the other rows for the cleartext to be revealed. Repeat the process (starting back at the first wheel if necessary) until you have decoded the full ciphertext.
Please note that this cylinder only shows half of the letters, for convenience make sure your message is not on the other half.