GN NETCOM 2393-829-109 JABRA BIZ 2300 Landline Telephone Accessory Air Shock Microphone -When the microphone is close to the mouth of the user, there is a risk of respiratory noise. To reduce it, the microphone is designed aerodynamically, and with many small holes instead of a larger hole Free Spin Boom - With Jabra's Free Spin boom you can rotate your boom a full 360 degrees. This lets you adjust your boom positioning so that it's always exactly where they need it - without having to worry about breaking it Crystal Clear Sound Clear sound is essential for a good conversation, call efficiency and accuracy. Digital Signal Processing in Jabra audio devices will remove background noise and echo as well as protect the user against sudden high peaks in volume