The S400 will use the mild hybrid system jointly developed by Mercedes and BMW and will be equipped with a lithium ion battery. The ML450 will be the first Mercedes application of the Two-Mode hybrid system. General Motors is building the Two-Mode hybrid transmissions for its own applications as well as supplying Chrylser. Similarly, Ruhl revealed that Mercedes would build the Two-Mode transmissions for both its own and BMW's vehicles. The X6 will be the first Munich model to get the hybrid treatment. The guts of the Mercedes-built units will be identical for both German brands and, like the American version, the only difference is the mechanical interface to connect the respective automakers engines as well as the control software. One item Ruhl declined to discuss is the battery for use with the Two-Mode hybrids. GM and Chrysler are both using nickel metal hydride. Mercedes is using lithium ion for the mild hybrid and the 'no comment' from Ruhl indicates that the same may be true for the Two-Mode.