These is the Polycom Soundstation 2 Computer Calling Kit.  The Polycom Computer Calling Kit enables your SoundStation 2 with display or SoundStation 2W to connect to a computer through the 2.5mm Applications Port built into the conference phone. This kit allows you to make conference calls over the Internet. You can now use your Polycom conference phone with Internet phone services such as Skype, MSN Messenger, and Yahoo! Messenger, as well as with computer-based softphone clients. Polycom part# 2200-07878-001