Product Serial Number ： 00249 Product Name ： Built-in Digital Video Recorder (Economic) Model NO ： VT-RI402 ● High performance, low cost. ● No operating system requirements. ● Two HD can be intalled, single HD support can be up to 120Gb. ● 4-channel video input, 2-channel video output. ● Real-time high definition display: NTSC: 720 X 480 pixels; PAL: 720 X 576 pixels. ● 4-channel sensing signal input, 1-channel alarm output.