The CTEK chargers are designed and tested/qualified in Sweden. They are manufactured in China to CTEK quality specifications..
This is a similar model to that used by a number of other recognised quality manufacturers.
The model is very different to the generic items, sold under many names, whose "design, test and qualification" is often carried under very different business ethics.
I, like many other modellers (mostly in the US) spent a number of years playing with far eastern petrol model aircraft engines which had the same form (but not the functionality!) as US/Japanese engines. You kept seeing the same engines being sold under different names and were in the most part completely rubbish. These would often last 3-6 months of flying whereas a Zenoah will easily last 10-20 years. Fortunately, I have my stockpile of new Zenoah's in the cupboard.
Ultimately, it is all to do with business ethics.
I found this yesterday - make of it what you will.
https://www.youtube.com/watch?v=tBg4ximDrsk