18 months and up. These chunky, interlocking builders are perfect for construction and fine motor play. The brightly colored pieces are perfect for children to build a variety of creations. This set universally connects with other builders. Includes a sturdy storage container with locking lid. Available in 72 and 144 piece sets. Four building boards are included with the 144 piece set only. Smallest block size is 1 1/4".