This product is either discontinued or we cannot get that from suppliers.
Plantronics Y-Adapter Digital Training Cable 79694-11, Mute And QD CLAMP, Easily connects at quick-disconnect QD connection, Training Adapter Cable, Audio Cable.
Plantronics Y-Adapter Digital Training Cable With Mute And QD CLAMP (79694-11) Y-Adapter, Trainer Cord, with Mic Mute Switch and QD Clamp for EncorePro 500/700 Digital Series Headsets.