There are three NICEHCK DIY PK2 versions for sale on that page:
https://www.aliexpress.com/item/201...d-Plug-Earplugs-Headset-Free/32801437048.html
1) Black version 3
2) Black version 4 (which is actually all white)
3) Black version 5
Is there a technical difference between version 3 and version 4, other than the color? Is one superior or an updated version?
Version 4 is a dollar more and even though it's called "black version 4" it's color is white. Typo on NICEHCK's part?
Since I am a mere customer of HCK, I do not know the details.
I hear that the driver of black version 1, 2, 3 are different.
And I think that parhaps the the driver of black version 3, 4, 5 are same, and only color of shells or cables are different.
Please listen to HCK's Jim during price negotiation for details and certainty.