Age 3+. The special pen does it all! 2 in 1 activities. A rainbow of colors appear like magic! Reveal the invisibly printed pictures and answers! www.leemagicpen.com. Facebook: www.facebok.com/magicpens. Conforms to ASTM D4236 - Non-toxic. From the makers of Yes & Know Game Books (Trademark of Stry-Lenkoff Co.). Printed in USA.