Defender Sentinel 8-Channel Smart Security DVR with 4 Cameras and 500GB HDD: * The Defender 8 Channel Security System with 500GB HDD is extremely easy to set up and use * View your footage live online, PC, Mac, iOS, BlackBerry, Android, Windows Mobile or Symbian devices * Instant email alerts if activity detected * 600 TV lines of resolution * The Defender 8 Channel Security System with 500GB HDD DVR records in 704 x 480 resolution * 36 IR ClearVu LEDs provide crisp and detailed night imagery * 500GB hard drive allows continuous monitoring and recording of over 2 years worth of footage * USB port for backup * Weather resistant cameras * Secure wiring can"t be tampered with * The Defender DVR Security System is expandable up to 8 cameras