Write secret messages to your friends and decode them with this ring. The Caesar Cipher is one of the simplest codes. Simply shift the alphabet by some amount and use that alphabet to write your message, or in this case twist the rings so that the letter line up in the right order.
This is actually 2 nested rings that print together and turn independently. It's big enough to fit on a finger tho it may be too big for regular wear.
Both ends of the message will need a ring. The first letter of the message should be the what A in the top ring alligns to in the bottom ring. When encoding use the bottom letters for the top when decoding use the top letters for the bottom and decode away!
H:FVB HYL H ZWF UVD