"Dear Rain Noe, thank you for the pleasant and interesting article. Always feels good to read an objective text that adds something new to our minds.I Googled about a bit and I believe the "waist fan" may be a Circular Fan, as I found the design to be in similar shape (but not foldable). Take a look on this one:https://youtu.be/U467pnMilxMHave a nice day!"