WARNING: This device is not intended for use in receiving audio through windows, doors, or any solid substance and should not be used as such as to do so many be unlawful. The P650 is the world`s most advanced electronic parabolic microphone. Developed over a three year period and constantly updated, this broadcast media quality parabolic microphone is in use around the world by federal and local law enforcement, surveillance professionals, professional nature observers, documentary film producers. If you have ever seen a professional football game telecast , then you probably seen on of these parabolic microphone in use on the side lines by network television personnel. This long range parabolic microphone is capable of picking up and magnifying audion signals up to 75 times that of a normal omni-directional microphone while remaining virtually impervious to overload . Powered by two 9 volt batteries, the P650 assembles ready for use in less than two minutes and comes complete with a built in microphone capsule, equalizer/amplifier in handle, earphone, aiming sights, effects/voice switch and one year manufacturer`s warranty.