Defender Sentinel 8-Channel Smart Security DVR with 4 Cameras and 500GB HDD: * The Defender Sentinel Smart Security DVR is extremely easy to set up and use * View your footage live online, PC, Mac, iOS, BlackBerry, Android, Windows Mobile or Symbian devices * The Defender 8-Channel DVR with 4 Cameras sends instant email alerts if activity detected * 480 TV lines of resolution * DVR records in 704 x 480 resolution * 24 IR ClearVu LEDs provide crisp and detailed night imagery * 500GB hard drive allows continuous monitoring and recording of over 2 years worth of footage * The Defender Security DVR with 500GB HDD has a USB port for backup * Weather resistant cameras * Secure wiring can"t be tampered with * The Defender 8-Channel DVR with 4 Cameras is expandable up to 8 cameras