This could be one major product that will be developed across content areas. There could also be multiple products developed under the direction of each teacher. Or, there could be one major product with multiple supporting products. In any event, the product(s) should support the project theme and, in some way, provide a solution for the problem statement or an answer to the driving question.
Example: Each Detroit teacher identified a major product that student teams were responsible for developing.
English Language Arts: Students developed position papers on the subject supported by research. History: Students researched the history that influenced the global warming debate. Chemistry: Students built working batteries that generated electricity. Computer Science: Students assembled and programmed autonomous, battery-operated Lego vehicles. Geometry: Students built to scale a model city to power their Lego vehicles around.