The RM685 is a two-channel Digital Video Recorder (DVR) by Black Box that is designed for a variety of video surveillance applications. It allows users to record, store, and access up to 16 channels of live video and 1 channel of audio. It features a built-in motion detection feature, allowing users to set selective recording parameters and create alarm triggers. Additionally, the RM685 also has multiple digital video inputs, as well as a variety of access control features that include time and date stamps, alarms, and up to 32 user IDs.