The 10342-E400A Collector Box Assembly is designed to carry the gas over from each burner to ensure that each burner will light quickly and safely. Not only that, but the ignition wires are designed to clip right into the collector box assembly, allowing each burner to have its own designated sparker. It is important to note that this Collector Box Assembly includes both 10342-E400 and 10342-E401 in one complete package. Essentially, you are getting both the top and bottom half of the stainless steel crossover tube.