Suspension bridge, truss bridge, cable stayed bridge. How many can you build with the shapes and pieces in each of these sets? Or build with more than one Mini Unit kit to expand the possibilities even further. These unique sets encourage explorative play and introduce math concepts, logic, and problem-solving. Ultimate Bridge Kit: 15 shapes, 19 wood bricks, 620 unit beams; Truss Bridge Kit: 220 pieces (WD1132, sold separately); Cable Bridge Kit: 200 pieces (WD1142, sold separately). No additional tools needed. BPA-free, 100% earth friendly, made with organic paints and dyes. Ages 6+.