For Unified Communications applications, choose the X200. Optimized for UC, the X200 incorporates echo cancellation and Digital Signal Processing (DSP) to give you the voice quality UC needs - just what you expect from VXi.VXi X200 USB Adapters- Optimized for Unified Communications.- Includes all the features and functionality of the X100 USB, plus an enhanced feature set.- One-touch answer/end call feature improves your productivity (dependent on softphone applications).- DSP and echo cancellation functionality eliminates VoIP latency and background noise.- Compatible with Windows, Macintosh and Linux operating systems.