2 years & up. These versatile hardwood-framed stacking blocks have six stacking squares and smooth, rounded corners and edges for safety, with inset magnified acrylic windows. The magnification stacking blocks are ideal for exploring natural, tactile, and other detailed materials found inside on in nature. This set also promotes fine motor skills and block play. Encourage children to build their own unique structures. Enhance STEM-based activities with this set, perfect for group or individual play. Use these blocks indoors or outside. Each block has 2x magnification. Stack blocks together to intensify. Largest square measures 7"W x 7"D x 2"H. Includes 6 squares.