Great fun for the little ones! How to use Galt Magic Coloring Books? The pen that comes out of the package is filled with water. When the pen is applied to black and white pages, colorful images appear. Colored images disappear on their own after a while and the pages return to black and white. These magic books, which can be used over and over again, consist of 6 special thick pages. The pen is included in the set. Book dimensions: 21 cm x 15 cm Age Group: 3+ Years