Rolex is similar to Apple in that they control most, or almost all, of their manufacturing and parts process. Rolex is one of the very few watch companies that

Rolex is similar to Apple in that they control most, or almost all, of their manufacturing and parts process. Rolex is one of the very few watch companies that produces their own movements instead of outsourcing them, or slightly modifying/customizing an OEM movement. Rolex has proprietary metallurgy for metals. They make their own stainless steal and gold for all their watches. The watch case is milled from a single piece of material, much like a unibody MacBook. I don't know as much about Leica, but Canon grinds and polishes their own glass for their lenses (the higher-end ones at least, not sure about EF-S lenses). Other companies create lenses with OEM's elements.