3 years & up. This set is the smallest of the hollow blocks with all the features of the bigger sets. Features include bamboo fasteners for a smooth surface (no visible screw heads), sanded smooth finish, and rounded edges for safety. Encourage children to identify shapes and use their imaginations to build wonderful structures. This set, perfect for small hands, will promote creativity. Pieces measure from 2 3/4" wide and up to 11 1/2" long. 24 pieces.