Popular Playthings Hexacus is stacking fun for everyone, and this 25-piece set provides twice as much fun as our original 12-piece set. Even very young children can play and build with these unique pieces designed for little hands. Children can sort the hexagonal pieces by size and color, then stack, nest, and balance them to create a wide variety of patterns and shapes. The Hexacus 25-piece set comes with an idea book featuring dozens of patterns and shapes children can build. Award-winning Hexacus was invented by world-renowned designer and artist Peer Clahsen. Playing with Hexacus is safe and fun for children age 2 and up. Popular Playthings provides award-winning toys that encourage learning, creativity, social interaction, and good old basic fun.