Amzer Privacy Protector Shield for iPhone 4 Prevent and protect your screen from unwanted peepers, while keeping the screen clean and unscratched. Screen will be completely black when viewed from left or right at the 35 degree angle. Maintain the privacy of your iPhone 4 screen when you are in a crowded area, such as bus, train, airplane, etc. Attaches smoothly with self-adhering surface; leaves no residue when removed. Privacy filter is manufactured to provide thick, durable, transparent surface without affecting the touch-screen features.