All these qi base are made in china, yijieneng is not the main manufacturer for them, they are just rebadged just like the others available, don't you see they all have the same packaging.
Also to note, don't you see many of the online stores are trying to get rid of them cheaply.
was just in china 2 days ago, and was offered them even cheaper, but after experienced there QC and the reliability of them i have rejected.
Samsung Galaxy S5 SM900F
Samsung Galaxy S4 Mini Duos I9192
Sony XBA 3
Sony MDR EX600
Sony MDR EX800ST
Xiao Mi Piston IF Edition