Meta Platforms plans to build only around a thousand units of the first generation of its augmented-reality glasses due out next year, a tiny batch that it will just use for internal development and to demonstrate the device to the public. And yet, to build the glasses, Meta is using a convoluted and expensive arrangement involving factories in China, Taiwan and the U.S.

That’s due in part to Meta’s decision to experiment with a special, pricey compound inside the lenses that because of government rules can’t easily be exported out of the U.S. As a result, Meta has to assemble the lenses in the U.S., while other parts of the glasses—the wristband that controls it and a wireless computing pack that acts as the brains of the device—are made in China and Taiwan, respectively.