Children's Building Blocks Crayons: The Collapsible Coloring Pen Set contains 12 buildable and detachable building block crayons that parents and children can use to assemble each section separately into models like rockets, castles, and more. Let children learn to draw while developing their hands-on ability, and enjoy the double fun of coloring and stacking. Adjustable Length & Easy to Grip: Rainbow crayons can adjust the color order or length according to your needs, the total length of a single crayon is about 9.25 inches, and a single saves 1.3 inches, each has 12 basic colors, just carry one to meet different writing or Drawing needs, great for kids' first crayon arts and crafts. Smooth Drawing & Safe and Durable: The building block coloring pen is carefully made with high quality paraffin wax and ABS, which is safe, non-toxic and environmentally friendly, with smooth lines and even coloring, will not chip, break or stain children's hands, which can bring fun to children And smooth coloring experience. Bright Colors & Attract Kids: This children's crayons are colorful and not easy to fade, each crayon is rich in 12 bright colors, just the right color harmony, can stimulate children's visual development and avoid visual fatigue. The rainbow-colored section design can stimulate children's curiosity and inspire them to draw and mark. Wide Use: The Multi-Color Stacking Crayons make drawing and art creation enjoyable and are the best essentials for kids. These colorful crayons can be used as coloring projects during arts and crafts, or as birthday party favors, children's day gifts, Christmas gifts, Halloween gifts, classroom rewards, and more.