I am not an expert in this kind of products but even so, I decided to change the battery of my Iphone 11 with Fix Kit (which according to sources seemed to be the best value for money) and, after a month, I can say that it seems to be true, it works perfectly, it is 100% healthy and it was relatively easy to put it in by watching a Youtube video. I can say that it seems to be true, it works perfectly, the health is 100% and it was relatively easy to fit it by watching a Youtube video. 5 stars. It doesn't overheat. And in addition, it has all the tools (to spare, it must be said) to make the battery change.