Aposonic A-S0402R21C H.264 CCTV 4-Channel Full 960H/D1 Real-Time Surveillance Standalone DVR, HDMI/VGA Dual Output, Mobile Access, Mac Ready (No HDD) 960H/D1/Half D1/CIF Real-Time Auto-Adjusted Recording / Playback Quality. Recording 960x480 / 720x480 / 720x240 / 360X240 at 30 FPS per channel. 1x HDD bay, support up to 4TB. 1x Audio-in / out, RS485 input x1. Firmware upgradable. Powerful Configuration capability of Live-view, Recording, Playback, Motion/Alarm, Backup, Remote access. Friendly Graphical User Interface. Dual streaming technology to encode recording stream and network stream separately. Support NAT function, QR code scanning by mobile devices. Live view and access control through Internet Explorer, Firefox, Chrome, Opera, and Mac OSX/Safari. Streaming live video / playback on mobile smart phones or tablets via free app.