This product is either discontinued or we cannot get that from suppliers.
Poly Plantronics 211019-01 Blackwire, Headset adapter, Interface USB, Left Connector 4 pin USB Type A, Left Connector Gender Male, Right Connector Gender Female, Red.
The Poly/Plantronics Blackwire USB-A Replacement Inline Control 211019-01 is a Plantronics inline control adapter that provides an easy control button for your headset while using.