Innovative Telecom SX8800-P2 USB/SD On Hold Music Player - Music & Message on Hold Multi-track Superior sound quality on any PBX or KSU phone system, USB Flash drive with over 15 mp3 files included. a Micro SD card slot is also provided. Plug and play -The included USB drive is preloaded with hours of royalty - free music and standard thank you for holding messages Auto Start -Automatically plays out of USB drive or Micro SD card Multi-track - Automatically plays up to 99 tracks then repeats