The Karpine proGuard HD clear screen protector for Samsung Galaxy Ace Duos affixes to your phone using a residue-free adhesieve layer. Because of its rigidity, the cover will not leave air bubbles when applied to your phone. Additionally, because the product is designed specifically for your phone, its easy to align correctly for simple application and adjustment. High surface hardness resists scratches and scrapes better than glass and Matte surface prevents fingerprint marks. Karpine proGuard HD screen protectors are rated at a surface hardness of 3H. This means it provides exceptional protection against scratches and scrapes. Special UV coating prevents sun damage and resists oil and stains. In order to provide the best possible protection for your phone while also ensuring a long-lasting film, Karpine proGuard HD have coated their screen protector with a special UV-resistant chemical. This prevents the sun from damaging or aging the screen protector, while also helping resist fingerprints, oil and staining.