Plantronics Compatible USB Adapter Cable With Volume Control And Mute Functionality (Connects With Any Wired Plantronics Headset with a Quick Disconnect) Connects Into A PC, Laptop Or Softphone.: Amazon.co.uk: Computers & Accessories
Plantronics APU-75 CS500 Series to PC Adapter 202678-01 202678-02
DA Series - Smarter digital adapters for Poly QD headsets | Poly, formerly Plantronics & Polycom