It is well-known that sound permeates through walls, doors, water, windows and other constructions as well as through voids, cavities and ventilation shafts. These outlets makes it possible to intercept conversations conducted within a room or any  premises with the help of highly sensitive contact microphones (electronic stethoscopes), window laser systems or conventional microphones without entering the room ( target area). For bigger areas get the DNG KIT1 a white noise generator kit that helps to keep conversations and information private. Have confidential meetings and speak freely in your office, conference room or any private space. This kits comes with the iProtect DNG 2300 3 channel  digital white noise generator, 12  transducer, and two speakers all in a aluminum case for easy transport.