Plantronics background noise suppressor ( BNS ) is for any Plantronics headset with a voice tube.  It directs more of your voice into the tube making the person your talking to hear your voice better and shield background noise from being heard.  For true noise-canceling, a noise-canceling headset is required which has a mic boom instead of a voice tube and electronically lowers background noise by up to 75%. The BNS slides onto the end of an existing voice tube.