Đàn môi

Đàn môi ((Vietnamese): Đàn môi, "lip lute") is the Vietnamese name of a traditional musical instrument widely used in minority ethnic groups in Vietnam. This instrument is somewhat similar to the jaw harp but there are some differences. Most Đàn môi are crafted out of a single piece of brass and attached with a string to a decorated bamboo case. Rather than being played against the teeth, like a jaw harp, the dan moi is played against the lips. This gives much more flexibility to player, leaving them freer to shape their oral cavity as a resonance chamber to amplify the instrument.

Đàn môi are a traditional musical instrument of the Hmong people.

...
Wikipedia