This document provides specifications for an ATDR-404 security camera system. It has 4 channel video inputs and 1 channel video output. It supports H.264 video compression and embedded Linux OS. It can record in D1, HD1, and CIF resolutions from the 4 video inputs in real time to 2 SATA hard drives with up to 2TB storage each. It also supports features such as schedule and motion detection recording, playback, backup to USB drives, remote access via browser or mobile apps, PTZ camera control, and alarm inputs and outputs.