Magician displays one card with its top corner torn and barely hanging on. Magician puts his empty hand around the other side of a glass door or window, keeping it there with its fingers spread wide open and palm visible. The other hand taps the card against the opposite side of the glass, and the card's top corner is visually seen to fall off the card into the hand on the other side - passing right through the glass. Impossible.
visual, extremely unbelievably easy to do can be performed on any glass window or door, even a car door