Cable stayed bridge (this item), Truss bridge, Suspension 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. Cable Bridge Kit: 200 pieces; Truss Bridge Kit (WD1132, sold separately): 220 pieces; Ultimate Bridge Kit (WD0472, sold separately): 15 shapes, 19 wood bricks, 620 unit beams. No additional tools needed. BPA-free, 100% earth friendly, made with organic paints and dyes. Ages 6+.