Nango
Major Contributor
Couple of far east Mfr of those IEM had to admit recently they did not built in the number of drivers they announced but only one or two where it said six. Also some of them announced to be beryllium coated where only plastic but cost north of 200$. Read on Head-Fi about it. Be aware, names were given as CCA and KZ among others with models featured by @crinacle who says "he knew nothing".
https://www.reddit.com/r/headphones/comments/t78yuv
https://www.reddit.com/r/headphones/comments/t78yuv