Truly the ULTIMATE in on-hold audio, the OHP-7500 can literally handle almost anything you throw at it. Whether you have your on-hold messages on an audio CD, SD memory card, or on your PC, this system can do it all. And, like all of our other systems, it?s very easy to use! The OHP-7500 works with virtually all analog and popular KSU-less phones. The 7500 also includes hold music activators that provide ?true? hold button activation of your on-hold audio when connected to the handset cord of each phone. Built-In Analog Phone Adapter Module - Add music-on-hold to conventional analog and KSU-less telephones with up to 4 lines and 50 station sets. Works with all types of phones... even cordless. Digital Flash Memory - 128MB of on-board flash memory stores over 480 minutes (sampled at 32kbps) of awesome-sounding content. Additional Secure Digital card (not included) can add over 70 hours of content for continuous playback (1GB SD card). Integrated CD Mechanism - Quickly and easily record high quality audio from an Audio CD. CD media is easy and inexpensive to duplicate and distribute. CD Autoload - drop in a CD, close the lid, and the unit automatically records the content. USB Connection - Connect to your PC via USB to add new content or update firmware. PC Connection...strictly optional - Unit uses PC only to update content stored in flash memory. Updated content can optionally be added by copying an MP3 or WMA audio file to a Secure Digital (SD) card without the unit ever being connected to a PC or network. Auto-start after Power Loss - If power to the unit is lost, unit immediately returns to continuous playback with all settings without human intervention. LCD Control Panel - 6-line backlit LCD panel displays ID-3 tags with descriptive names of tracks for easy identification and selection. Display also shows a variety of important information so user can choose playback preferences and easily determine unit's operational status. Built-In Monitor Speaker - Allows user to monitor sound with the flip of a switch. Wall-Mountable - Unit can be mounted, played and recorded in a vertical position. HoldTracks Audio CD - Choose new, royalty-free music from a prerecorded audio CD featuring a variety of music styles. MessageStudio Software - Allows users to create new on-hold audio content, with voice, and music on their PC with a few mouse clicks. Then, just transfer the file directly to the unit?s on-board memory, to an SD Card, or upload to a server for a network update.