Children can keep their secret formulas safe with the Ada Twist Scientist Light and Reveal Pen. Inspired by the Netflix show Ada Twist Scientist this light and sounds pen looks just like the one Ada uses from the preschool show and comes with a notepad kids can use to doodle or write private messages. Write on the notepad using the pen and shine the light to reveal the hidden message. The pen even features buttons children can press to hear fun phrases or play the The Hypothesis Song ! Aspiring scientists will love singing and dancing along to the music as they write secret messages and reveal them to only their closest curious friends! Bring home the Ada Twist Scientist Light & Reveal Pen and the rest of the Ada Twist Scientist toys and let your child explore the fun of friendship scientific discovery and teamwork. Requires 3 x AG13 batteries (included). Ages 3+