P/N: 202581-01 The Blackwire 725 USB headset offers Active Noise Canceling technology, hi-fi stereo performance and all-day comfort so you can tune into work, and tune out noise. FEATURES Active Noise Canceling Smart Sensor Technology Professional Audio Quality Inline Controls Music/Multi-media Durable carrying case SPECIFICATIONS Connects to PC and Mac via USB Ideal for Users in noisy environments with PC/Mac audio communications; featuring smart sensor technology Audio performance Active Noise Canceling (ANC); Dynamic EQ: microphone frequency response 100 Hz–8kHz optimal for wideband voice telephony (up to 6,800 Hz), hi-fi stereo output from 20 Hz–20 kHz, enhanced digital signal processing (DSP), noise-canceling microphone Hearing protection SoundGuard: Sound leveling for listening comfort and acoustic limiting for protection against sounds above 118 dBA Models C725 (stereo): UC Standard version built for UC applications and softphones from Avaya, Cisco, Skype and more* C725-M (stereo): Version optimized for Microsoft Lync