This is a non polarized 2-wire Night Vision Color Intercom system that utilizes advance digital signal processing. It is expandable up to 16 color monitors and could be fitted for a variety of installations. The system utilizes 2 wires throughout the installation. VIDEO INTERCOM SET OFFERED HERE INCLUDES: ONE single button anti-vandal weather protected outdoor station, TWO 7 inch touch screen color indoor monitors, ONE 100 W power supply PS5-24V, ONE DPS Power Separator. MAIN FEATURES: Touch Screen Color monitor; Night Vision Outdoor Station; Expandability up to 4 outdoor stations, 2 CCTV Cameras, light control and 16 Monitors; Image storage on flash memory; Download images to SD card (NOT INCLUDED); T-View Photo software; Answer Front door calls in any room; Remote Door Lock Control; Entrance Monitoring; Intercom calling between Rooms; Flexible wiring options for single or multilevel configurations. OUTDOOR STATION FEATURES: High quality CCD night vision color camera; Rugged ant vandal stainless steel panel; Call Button; back lit name plate; Unlock Electric Lock. MONITOR FEATURES: Digital TFT Touch screen and panel; 12 selectable tones could be assigned to calls from different doors (optional for more than one outdoor unit); Day or Night Ring Tones; Mute ring but monitors and outdoor video and audio will be turned on; 120 MB flash memory image storage (could be downloaded to SD card); Image recording options: Auto-Recording (default), 3 Seconds later the monitor will start recording the images automatically; Unanswered calls recorded images indicated by a flashing LED; Manual recording when video is present; Select image recording rate; On Screen Browsing; zoom to full size by touching the image; Auto Slide Show 5 seconds per image; Manual Slide Show moving your finger left or right from one to the next image. Recommended Wire for main bus: 2 conductors, twisted, unshielded, each conductor 14AWG and stranded.