Valcom V-9989 Multi-Messager USB Deice Built in monitor speaker; Active output indication trigger; LED status indicator; No drivers or special software; Triggered and/or timed playback; Multi Messager USB Device; Up to 4GB flash drives supported Store up to 99 messages Auxiliary 12VDC output for wiring sensors Playback quality up to 128kbps Plays MP3 files from USB flash drive