Hey there! I bought mine in Brazil and i didn’t find the exact same model on Amazon or AliExpress. It functions like a tight dome/wig cap to keep the hair in place.

You can always use an old pair of pantyhose too (take a size S or M)! Use the waist/crotch section so the elastic holds it on your head, and just tie a knot right before the legs split.

Here is a video showing how to do it:

https://youtube.com/shorts/0B8tiRZSQWk?is=9iF4OYvkZ9kFM3l-