The “Nectar” was tightly packed with miniaturized versions of all the components needed for a fuel cell:  valves, pressure regulators, pumps, O2 and fuel sensors, the fuel cell itself, manifolds, electronics modules, heat exchangers, and even a muffler.  Dave Brancazio worked with a talented team working very hard to get these components designed, manufactured, and tested on a tight timeline. The team literally negotiated over millimeters, i.e. “May I have an extra millimeter in the x direction?”