Q:Is there any quality assurance?  

Warranty for 3 years. We have different warranty policies for different after-sales time. 

For the first year, you may get a new one for free if you replace it with an old one. And for the second and the third year, you may get a new one for free if you replace it with three old ones. 

If you have any other questions, do not hesitate to consult our professional sales experts.