Plantronics Voyager 4210 Bluetooth Mono B4210T. Plantronics Voyager 4210 Mono Bluetooth Headset B4210T. Plantronics Voyager 4210 Bluetooth Mono wireless headset without BT600 USB Bluetooth adapter. Plantronics Voyager 4210 Bluetooth headset is a "single" ear headset.
eBay