The Secure Headset Group® (SHG) S D144-AMP 4-wire adapter provides SHG QD (quick disconnect) to a PJ7 2-prong mute and volume control.
 
The dual-prong adapter works with any headset (SHG, Poly/HP, etc.) top in 4-wire and plugs into consoles, PBXs, and ACDs.
 
Automatic Gain Control for MindShare Consoles.