Amzer Kristal Tempered Glass HD Screen Guard Scratch Protector Shield for Apple iPhone 4/4S - Retail Packaging The slimmest & stronger HD screen protector than regular. Easy to install with a simple swipe. Its Premium Tempered Glass prevents the glass from shattering. Round edge borders avoid chipping while using it with Amzer cases. Scratch resistant material protect your iPhone 4/ 4S from sharp objects also like keys, knife etc. Tempered glass technology prevents the glass from shattering while facing heavy impact.