Know your gear
Headset adapter cable for Cisco Cordless IP phone model 7920.
This Plantronics cable has a special 2.5mm plug adapter with 4-conductors (3 black bands). The other end of the cord has QuickDisconnect to snap together with the Plantronic H91-CIS or H101-CIS headsets. These two models are specially engineered with increased RF shielding to mitigate any buzzing sounds due to the strong signal of the cordless phone.
This Plantronics cable has a special 2.5mm plug adapter with 4-conductors (3 black bands). The other end of the cord has QuickDisconnect to snap together with the Plantronic H91-CIS or H101-CIS headsets. These two models are specially engineered with increased RF shielding to mitigate any buzzing sounds due to the strong signal of the cordless phone.