Unfortunately, I bought two of them and both had a problem at the bottom of the screen where it seems like there is air trapped, but no matter how much you press, that line remains. Maybe I got defective ones... Maybe because the phone is already an old model, the screen has been affected by time if the glasses are old

A screen protector that has nothing to envy from other expensive ones I have used on the same phone. It has excellent application, with the case I use I have no issues and it does not affect the touch at all. In the first serious drop, it left a mark but I consider it normal, after all, that's why we get them, to protect the main screen.