Chosen Solution

I bought this case Click What you think guys is that safe to use on my iPhone 6 Plus all the time? I will recieve within 1-2 weeks, and if it really have 5000 mah battery build inside the case (which is looks like nice on the images) it can be awesome on my 6 Plus. Can it damage the phone battery? Will it damage? Can it make any problem for me?

I am sure that the apple battery case wont damage it