Include More People On Your Web Conference Calls With The Mxl Ac-40Ext Microphone. Connect Up To Four Of These Extension Mics To Either The Ac-400 Or Ac-406 Central Usb Mic. Each Ac-40Ext Has Its Own Mute Switch To Enable Private Conversations. The Sturdy Metal Construction Makes The Ac-40Ext Perfect For An Office Environment Or Conference Room. Conduct Meetings Over The Web With Superior Clarity Even With Multiple Participants. A 6 Ft. Cable Is Included To Attach The Ac-40Ext To Either The Ac-400 Or Ac-406.