Convert your exist wired landline RJ9 plug headset into USB plug headset for computer PC laptop mac tablets softphone. SEE COMPATIBLE LIST IN DESCRIPTION BEFORE PURCHASE. Work with RJ9 headset compatible for Plantronics Avaya Nortel NT Yealink Aastra Nothern Telecom Polycom Shoretel Polycom Toshiba Siemens Viop POE NEC Mitel Office Desktop IP Telephone. Work great with wireless headset systems following only, compatible for Plantronics CS50, CS55, CS351n, CS361n, CS70n, CS540, CS530, CS510, CS520, C054, C052, Jabra Pro 920, GN9125, GN9120 or Sennheiser D10 wireless headsets. NOT compatible with EHS cable. Easy setup, no extra software drivers. Need change your computer device sound audio setting to USB device : In windows click Start > Setting / Control Panel > System / Hardware and sound > Sound , Make sure USB device shows a green check mark in Input / Recording and Output / Playback tabs NOTE : if get no microphone then check the settings on computer/laptop or softphone app you are using, need to change microphone input setting to USB or try different input setting and it will work. In some plantronics wireless headset model, customer change the dial + slider setting underneath the base and it work. Convert your exist RJ9 or wireless headset into USB plug headset for computer PC laptop Softphone. Work with RJ9 headset compatible for Plantronics Avaya Nortel NT Yealink Aastra Nothern Telecom Polycom Shoretel Polycom Toshiba Siemens Viop POE NEC Mitel Office Desktop IP Telephone. Work great with wireless headset systems, compatible for Plantronics CS50, CS55, CS351n, CS361n, CS70n, CS540, CS530, CS510, CS520, C054, C052, Jabra Pro 920, GN9125, GN9120 or Sennheiser D10 wireless headsets. NOT compatible with EHS cable. Easy setup, no extra software drivers. Need change your computer device sound audio setting to USB device : In windows click Start > Setting / Control Panel > System / Hardware and sound > Sound , Make sure USB device shows a green check mark in Input / Recording and Output / Playback tabs. NOTE : if get no microphone then check the settings on computer/laptop or softphone app you are using, need to change microphone input setting to USB or try different input setting and it will work. In some plantronics wireless headset model, customer change the dial + slider setting underneath the base and it work.