The New SX2LP music on hold device for use with all 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 Flash then Hold Activation on any 2-4 line telephone To place callers on Hold simply press Flash then Hold, to go back simply return to caller and voice deactivate or press Flash. Hold Activation on any PBX telephone or many compatible 2-4 line phones Simple to install - 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 - the included 128MB USB Flash drive is preloaded with hours of great sounding fully licensed music and messages- Ready to go right out of the box (including some Holiday files) Customizable 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 ON-OFF 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 and AC adapter (universal 110V-240V) included