Have you ever noticed how great inventions are almost always invoke the feeling of "Oh, of COURSE! I should have thought of that, it's so obvious."? In the house I'm in right now, I can't even hear the doorbell upstairs in the master bedroom. It's 3 flights up from the chime. But if someone opens the front door, the change in air pressure is immediately obvious to the point where you can hear it. Someone used this effect to create a house alarm. AirBlock instantly detects the change of air pressure from the forcing of all windows and doors in areas as large as 4,000 ft.� (370m�). I think this is a great idea. You don't have to wire all your doors and windows, and the detection system is almost unbeatable. To bypass it, you'd have to slowly feed in air into the home to equalize the pressure before opening the door or window. Unless you're Aldritch Ames or someone else keeping Top Secret documents in your house, I doubt any crook will take the time to do this. Add yet another neat toy to the collection!