This product is either discontinued or we cannot get that from suppliers.
Poly Plantronics External Ring Detector Spare Cable 75010-01, External Ring Detector Cable, Adds ring detection to a headset, Compatible with Avaya phones & Plantronics headsets.
Quality sound performance makes the Plantronics .Audio PC Microphone ideal for Skype, Windows Live, and Yahoo! Messenger calls. Place it on your desk for maximum stability or mount it on your PC monitor.