MAGIC WATER BRUSH: Just fill the drawing pen with water, no need for ink, non-toxic and safe to use, won't dirty baby's clothes when painting, use the water brush to play with your baby's imagination and reap more fun. LEARNING HELPER: These water pens help kids develop creativity and learning skills, ensuring uninterrupted doodling fun and creativity. CONVENIENT TO USE: Please unscrew the nib, fill it with water, and then soak the nib in the water for more than 10 minutes until the nib is fully expanded to avoid water droplets, the first time you use it, it will make you draw more smoothly. EASY TO GRIP: The water pen is compact and lightweight, easy for little ones to grip. EXCELLENT GIFT CHOICE: The water doodle pens are a great gift to give to give to kids, can be applied to a variety of doodle pads or watercolor books, they will love this gift.