Logitech GROUP Expansion Microphones Only - microphone set - 989-000171 - Video Conference Systems - CDWG.com
Logitech Meetup with Expansion Mic Rentals - Rentex
Amazon.com: Logitech Expansion Mic for MeetUp, Plug-and-Play, Indicator Lights, Microphone Type Mono, Wideband, Noise Canceling, PC/Mac/Laptop/Macbook/Tablet - Black : Electronics