This unit is totally self contained with a hidden camera, alarm clock radio with a built in motion activated DVR, with 540 lines of resolution, 0.001lux low light color camera for better performance in low light performance, removable SD Card stores up to 32gb of video, for days of recording, and with a full overwrite function. In addition, the radio may transmit the video and audio to another room via a ¼ watt 16 channel video transmitter. Available in L, S, and C bands. The matching receiver is available from Covert Systems as the KSR-3575. The memory plays back is in AVI format for quick and easy viewing in MPEG-4. This unit sold only to law enforcement.