Large size is designed to be easy for young children to play with. The soft material means play is safe, even if the blocks take a tumble. Lightweight construction means parts stay together for imaginative play. The blocks float! Patented magnet design allows magnets to always attract. STEM: Engineering for young children. Teaches, colors, shapes, and building. Also encourages fundamental spatial awareness and thinking skills necessary for later success in STEM subjects. Includes small children's story about their Blockaroo kit, to connect kids, parents and their Blockaroos! Expanded assortment available online. This item not carried in store.