The big Autobot boss man himself get into the Alternators line, but at the same 1:24 scale as the rest of the assortment. As such, Optimus Prime did not turn into a semi-truck, but rather a faithful recreation of a Dodge Ram SRT-10. This model of truck had the supercharged V10 engine also found in the Dodge Viper, hence the inclusion of Viper branding on his chassis.
The combined form of the Universe Micromaster Aerialbots is Superion, an amalgamation of six robots plus their pack-in accessories that serve as connectors, head, and extremities of the gestalt warrior. While in Japan, the original source of the design ( Sixwing , 1992) was available in a collected set, this combiner needed to be purchased one bot at a time in the 2007 Universe release.
