Zmodo 4 CH H.264 Real-time Security Surveillance DVR System -3G Mobile& 500GB Hard Drive View Video Online with No Service Fees - View your DVR's live or recorded video footage on any PC. Long time recording: - Base on the H.264 Compression, maximize the hard drives recording time, as well as transfer video for viewing over the internet. Network Remote Access - Access live video footage directly from your mobile phone or PC anytime anywhere Advanced Motion Detection Recording - This allows you record only when motion is detected. Instant Email Alerts if Activity Detected - This system is designed to send an email alert, complete with photo of the activity, if any motion is detected, or if any camera experiences video loss.