Plantronics 26716-01

M12/M22 Amplifier Cable - Cisco IP Phone Cable
$19.95 from an Authorized Plantronics Distributor
 

Plantronics 26716-01 cable is the bottom coiled cable that plugs between the Plantronics H-series headset and Plantronics M12, M22, M10, or  MX10 amplifiers.  The 26716-01 is also used as a direct connect solution when you plug any Plantronics H-series headset into a Cisco VoiP telephone.  When used with the Cisco telephone, no amplifier is used.