In-line Mute Switch For All Plantronics QD Compatible Headsets - PLT QD's on both ends - add a mute switch to your corded headsets Plantronics compatible quick disconnects on both ends To add a mute switch to your corded headsets Headset has to have a PLT compatible QD,VXI P Series, SC P Series,Starkey PL Series Will work with H/HW series, VXI P series, Smith Corona P series, Starkey PL series Contact Headset Solutions 888-888-9031 with any questions regarding compatibility