Boom Microphone Design, 100 Hz to 10 kHz Microphone Frequency Response, 32.00 mm Driver Size, Leatherette Cushion, On-Ear Earpiece Design, Binaural Listening Mode, 32 Ohms Impedance, 1 x USB Type-A Host Connection, Over-the-Head Wearing Style, 02 Years Limited Warranty. Ideal for noisy work environments, the Blackwire 8225 On-Ear Stereo Headset from Plantronics features a swivel boom microphone with four integrated digital microphones, Acoustic Fence and hybrid active noise cancellation technologies.