Please note this device works by pressing Flash Then hold The Image Audio SX2LPS music on hold system for Landline phones (regular corded or cordless 2-Line or 4-Line telephones), plays music and messages for up to Two On-Hold callers with continuous playback. (unlimited callers with PBX telephones) Simple activation To place callers on Hold simply press Flash then Hold, to go back simply return to caller and voice deactivate or press Flash. Simple to install 1 minute installation - just connect to one corded phone or to cordless base and all phones and extensions work. Simple to update To add new audio content just copy any MP3 file from your PC to the USB flash drive - Included 128MB USB Flash drive is preloaded over 50 files with hours of great sounding fully licensed music and messages- Ready to go right out of the box (including some Holiday files) Customize-able Simple to use utilities software: allows quick and customized on-hold audio via your PC High capacity High quality audio playback and multi-track capability allows 1000 hours of playback time (via a 8GB USB Flash drive) Sleek and compact ABS plastic enclosure with wall mount capability built to perform in the toughest environments Built-in speaker- monitor the audio with simple switch Pre-loaded USB flash drive & SD card slot provided (SD card not included) Holiday On-Hold No moving parts - 100% digital Wall Mountable LED lights to indicate playback & On-Hold status Multi-track capable - plays up to 99 tracks then repeats Custom utilities software Auto-start after a power outage Volume control One telephone cord, AC adapter (universal 110V-240V), USB Flash drive with 50+ files, wall mount screws, audio editor and manual included