USB Cord all all Plantronics QD compatible Headsets - w/volume and mute - For H/HW Series, VXI P series, Smith Corona P Series, Starkey PL Series For any Plantronics QD compatible headsets like their H/HW Series Works with Smith Corona P Series, VXI P series, Starkey PL Series, any PLT QD compatible headset Has volume and mute function on cord Plantronics compatible quick disconnect on one end, usb plug for your computer on the other Plug and play operation - Can use to replace the discontinued DA40 USB cord