ZOSI 4 Channel 720P HD DVR 4 X 1280TVL Indoor/Outdoor 100FT Night Vision 3.6mm Cameras Metal Housing Home CCTV Surveillance Security System 3G Smart Phones/Internet Access QR Code Scan NO HDD 1. H.264 4Channel 720P AHD DVR with 4 High Definition 1.0 Megapixel 1280 TVL (720P) Heavy-Duty Metal IP67 indoor/outdoor weatherproof Cameras.***NO Include Hard Disk***you need to install Hard Disk for record &Playback. 2. DVR Equiped with HDMI/VGA/BNC port for multi video output, 720P Recording Resolution. HDMI Port for 1080P High Resolution Viewing. 3. Support USB port Back up , gives you the easiest option of backing up and transferring your video footage to a USB flash drive 4. Email Notification & Mobile Push Alerts when Motion Detection, Free ZOSI VIEW Apps for Live View and Playback on Smartphone ( iPhone, iPad and Android devices ) 5. Install video for your refer : http://youtu.be/9Zqy3WnSzcM . Two year quality Warranty !Life time Tech Support !