The 5200 Series Poly Blackwire 5220 headphones are designed for those who spend many hours on the phone or in video conferencing. With dual connectivity (USB-A and Jack 3.5mm ), these headphones offer exceptional versatility: they can be connected to the PC/Mac via the USB-A receiver/controller or directly to smartphones and tablets via the 3.5mm connector. The two-nautical ergonomic design (Duo) allows total concentration by isolating environmental noises, while the ultra-soft memory foam bearings ensure prolonged comfort throughout the working day. The noise cancelling technology of the microphone ensures that your voice is always clear, eliminating the background disturbances typical of the open space offices or the home environments. Specifications Brand : Poly (Plantronics) Model : Blackwire 5220 (C5220) Type : Stereo (Binaural) Connectivity : USB-A (by controller) and Jack 3.5mm Audio : Wide band (Voice), Dynamic EQ optimized for voice and multimedia Microphone : Noise cancellation with flexible arm