Easy Mirek190 ROM selector/downloader
Updated with V 4.2 links

Teclast X98 Air II

Teclast X98 Air 3G C5Jx

Teclast X98 Air 3G C6Jx

Teclast X98 Air 3G C8Jx

Teclast X98 Air 3G C9Jx

 

Apart from this, you can also try to install RemixOS on my of the above device. Here are the links:
Remix OS 3G – Non Root (Latest build) – This cannot be rooted as of now. If you want to add root functionality, download from below link.

Remix OS Air 3G C5J6 (Most stable + Rootable) Tested + Phone & Message Function Preloaded
Remix OS Air II – Pre Root

 

 

Stay tuned for more remixOs posts.