The Secret Messages Kit teaches kids the basics of cryptology, ciphers, and hidden messages. 18 different missions are included which teach kids how to use invisible ink, the Caesar Cipher, Keyboard Cipher, Telephone Cipher, Cipher wheels, the Polybius Check board, Braille, and more! Kids will be able to send and receive secret codes from friends using the spy decoder kits, invisible ink markers, and instruction booklet.The Secret Messages Kit includes:2 tubes,4 red caps,2 markers,4 crayons,Red plastic,2 fasteners,8 cipher wheels,2 cipher cards and two 48-page manuals