In April 1977, Jobs and Wozniak introduced the Apple II at the West Coast Computer Faire. It is the first consumer product to have been sold by Apple Computer. Primarily designed by Wozniak, Jobs oversaw the development of its unusual case and Rod Holt developed the unique power supply. During the design stage, Jobs argued that the Apple II should have two expansion slots, while Wozniak wanted eight. After a heated argument, Wozniak threatened that Jobs should "go get himself another computer". They later agreed on eight slots. The Apple II became one of the first highly successful mass-produced microcomputer products in the world.