The ahd-pir 18 is an hd spy camera hidden in a pir motion detector housing with invisible infrared night vision. this is a full 1080p ahd cctv camera with a built-in audio surveillance microphone. the 940nm ir leds are hidden behind the pir sensor window which makes this camera completely covert even when the ir leds are on. 940nm leds do not traditional infrared cameras. the 3.7mm fixed pinhole lens provides a wide angle of view that is ideal for most applications. it captures a field of view of about 90 degrees. check out these 1080p surveillance photos captured using the ahd-pir18. you can also watch this demo video and hear a demo of the built-in audio surveillance mic here. the built-in microphone is optional to use. simply connect the rca output of the mic to an audio input on your dvr to capture audio surveillance.