Girls Only! Secret Message Lab keeps secrets safe and teaches the science behind the mystery! This science kit contains everything young girls need to know to create codes and write secret messages. Girls will discover the science behind using acids and bases to make invisible ink, reveal mysterious messages using colored filters and light waves, learn to write their own secret codes, and much more. Using the two Magic Lock cases there are enough materials included for two girls to share and protect messages. This set includes 2 Magic Lock secret cases, 2 cipher wheels, 2 invisible ink pens with Ultraviolet reveal lights, 2 red acetates, 2 code wheels, 2 red and 2 blue markers, 2 white crayons and 24-page full color book which includes science information, facts about how codes have been used throughout history, as well as activity instructions.