Amplifier Replacement Coil Cord for Plantronics Headsets - QD to RJ11 Cords to works with M10, M12,AP15 Plantronics Amplfiers and Headsets Goes from the Amplifier to the PLT QD Compatible headset, PLT QD curly cord to RJ9/11 Clip Works with Smith Corona P series, VXI P series, Starkey PL Series, H/HW Series Headsets CONTACT us PRIOR TO ordering with any questions regarding compatibility Will work direct in on the Cisco 7900 Series phones, generic version of plantronics amplifier cords