This protector relies on an edge adhesive as opposed to others that the entire back surface of the protector clings to the phone. Since the S9 has a curved edge, the shape of the protector is really important. The shape of this glass protector was a good, but not a great, match to the S9 screen. Result was poor sensitivity in upper right area of screen and tendency for screen protector to separate from phone starting in that area. Even a simple fumble of the phone in your hands could cause the protector to separate. Almost need to be more careful with handling the phone with a screen protector than without it. Not much help to me.