The latest addition to the single and multi-touch Visualplanet Touchfoil is a flexible rear-projection film that can be fitted easily inside exterior windows, or behind interior flat or curved glass panels, to allow interactive media to be touched from the other side of the glass or in the street. Capable of being manufactured in rolls up to 13 feet long, Visualplanet’s flexible Touchfoil is supposedly as easy to apply to a window as a large sticker.

You can see all the specs here: http://www.visualplanet.biz/what-we-do/