Unique design allows for use over the head or over the ear Quick Disconnect lets you keeps your headset on, but unplug it from your phone. Requires amplifier (sold separately) . Noise-canceling model features unidirectional microphone. Plantronics (R) H171N DuoPro (TM) Convertible Headset With Noise-Canceling Microphone is one of many Headsets & Microphones available through Office Depot. Made by Plantronics.