Impact glass is made with three layers; two outer layers of glass and the inner layer consisting of polyvinyl butyral (PVB). When these three layers are fused, they become much stronger than standard glass. That being said impact glass can be broken but not easily or quickly. In areas that are affected by hurricanes, it is recommended to have shutters over your windows or to have impact-resistant windows. With their splintering effect (like a car windshield), this prevents it from breaking instantly, slowing down how easily something or someone can enter into your home. Although they are not indestructible, they are one of the best defenses you could place to protect your home.