Poly Blackwire 7225 ANC USB Headset - Black - Codecs: 24-bit audio at up to 96 Khz sample rate - Receive audio performance: Active noise cancelling (ANC) - Receive frequency response: 20Hz – 20KHz - Speaker sensitivity: 127dB ±1.5dB - Speaker impedance: 32ohm - Speaker size: 32mm - Microphone and technology: Four omni-directional mics - Mic frequency response: 100Hz–10KHz - Microphone sensitivity: -26 dBFS +/- 3dB - 211144-01 - 2 Years Limited Warranty