The Cipher wheel is a form of decoding known for hundreds of years, and here it is, where you can be the next to use it! Just align a specific letter on the inner wheel with a chosen letter on the outer wheel and keep the wheel still. Repeat this process until you have your letter encrypted! When printing, you generally can use any filament although I would not recommend flexible filament. To assemble, put the large and small wheels through the long stick with the small wheel on top of the large wheel and you will have a great cipher wheel that easily fits in your pocket.  Good luck encrypting and decrypting!