Poly - Blackwire 3210 - Wired, Single Ear (Monaural) Headset (Plantronics) with Boom Mic - USB-A to connect to your PC and/or Mac - Newegg.com
Amazon.com: Plantronics Blackwire C3215 Mono Headset with USB-A & 3.5mm Connection, Noise Cancelling, Soundguard and Flexible Microphone Arm - Black : Everything Else
Plantronics Savi Wireless Headset System Mono Wireless BluetoothDECT 6.0 590 ft 20 Hz 20 kHz Over the head Monaural Noise Cancelling Microphone Noise Canceling Black - Office Depot