Oversized hollow blocks for giant creations! This 16-piece set is constructed of birch plywoods and solids. Edges are rounded and surfaces are sanded smooth for safety and hours of creative play. Blocks are sealed and finished inside and out. For indoor use only. Ages 3+. Largest block measures 15.5"W x 8"D x 4"H. Smallest block measures 4"W x 8"D x 4"H.