3 years & up. Endless design and engineering possibilities! This complete set of eco-friendly mini unit blocks provide children with meaningful architectural and construction experiences. Curves, arches, wedges, ramps, and various segment pieces facilitate imagination, planning, and critical thinking while achieving the creation and completion of functional structures. Playing with Mini Unit Bricks® introduces children to: basic STEM concepts, the development of critical thinking skills, and the concept of planning, developing, administering, and completing ideas. Largest block measures 5.5"L x 1.5"W. Set includes 40 pieces.