Vietnamese site Tinhte.vn.
The video claims to show the new iPhone headphones and compares them to the old iPhone 4S headphones. A rough translation of the video's voiceover is below:
In my hands are the new earphones for the iPhone 5 that is about to come out - Apple's next generation of iPod [sic]. These will replace the current earphones that are on the market. These are manufactured at Phax Co factory in Vietnam [which could explain how the site got its hands on them].Don't worry, Apple's BFF Foxconn isn't being "aced out of" business. According to Tinhte.vn, the new headphones are being manufactured in Vietnam, but at a Foxconn plant. You can see in the image above the text read in the voiceover, about the design and manufacture.
The integrated design is characteristic of Apple products. Here I have the old earphones for comparison. The new ones are much smaller; when they are worn, they do not hurt the way earbuds do.
You can see on the old ones the surface is a separate part that looks like it can be detached, unlike the small surface of the new one. The old earphones were mostly made in China, with some in Vietnam, but the new ones are clearly made in Vietnam.
(Reading from the earphone wires: "Designed by Apple in California, assembled in Vietnam.")
It's possible these are third-party headphones with faux labeling on the wires. Or it could be a real iPhone 5 headset. As with all these numerous iPhone 5 rumors, we won't know for sure until the Apple event - also rumored - on Sept. 12.