The Slinky Secret Messages kit is the fun way to learn about cryptology-the science of secret messages! Explore the methods behind codes; ciphers; hidden messages and more! With duplicates of all contents this complete kit contains everything you need for you and a friend to send secret coded messages just like real spies! This kit contains two manuals; two tubes; four red caps; two markers; four crayons; one red plastic screen; two fasteners; eight cipher wheels; and two cipher cards. Recommended for ages 8 and up. Not for children under 3 years.