Zagg InvisibleShield Dry Full Body Protective Film for Nokia Lumia 920 Clear Screen Protector (3 Pack) Military Grade: Created from a resilient film that was first used to protect U.S. Military helicopter blades. Nano-Memory Technology: Features unique properties to provide self-healing and unrivaled abrasion resistance. Lifetime Warranty: If your InvisibleShield ever shows signs of scratches or wear, we'll replace it, no questions asked, for the life of your device. Front and back protective films offer full body protection. Easy Installation Pack of 3