NO-MESS ACTIVITY BOOK: Melissa & Doug On the Go Water Wow! Sports Activity Pad features reusable pages that come to life when wet. 4 REUSABLE WHITE PAGES: Use the pen to fill in each activity and see hidden colors and pictures appear with every stroke! Then simply let the page dry to erase the pictures and fill it in again and again. REFILLABLE WATER PEN: This activity book comes with a chunky-sized water pen designed for smaller hands to easily grasp and fill. The compact, spiral-bound format is great for travel.