Basic 40pc Block set (assorted sizes and colors). Award-winning ImagiBRICKS Giant Building Blocks are an enduring classic that offer endless play possibilities because they are versatile (build with them, jump over them, crash into them) and safe. Constructed of lightweight corrugated cardboard, if the blocks tumble, no one gets hurt! The blocks are printed with non-toxic inks and with their water-resistant coating are strong and durable for years of creative play. Because Imagibricks are b unit blocks , they can even be used to teach basic math skills. The blocks come in three sizes and colors and are available in various sets: the large red brick is 12 x 6 x 3 inch, the medium yellow brick is 6 inch x 6 inch x 3 inch, the small blue brick is 6 inch x 3 inch x 3 inch.