Anti-shatter film provides protection from flying glass in the event of a natural disaster or demolition by pirates. It forms an almost invisible protective coating on the glass surface. This window film should only be applied to flat glass. It should never be applied to polycarbonate (plastic). Adhesive window films are constructed from a multi-lamination of micro-thin polyester. They also have a scratch resistant coating to protect the film surface and enhance durability (except films for external application). The film should be cut 10 mm over size in both dimensions, and trim around the oversized edges using a sharp trimming knife after squeezed the film.