Plantronics C520 Blackwire is a dual-ear USB stereo headset. When a call comes in, just put it on; its Smart Sensor technology automatically answers and provides audio alerts to manage connection, mute, and volume status. With wideband audio, noise-canceling microphone, and hi-fi stereo you always get clear, natural, and rich audio. And the unique Dynamic EQ feature adjusts and optimizes audio settings on the fly, creating the best sound for voice, music, or multimedia. The Blackwire C520 Series is a business-quality communications solution bringing unmatched audio quality, all-day comfort, and easy portability — all in a compact, durable package for smarter workers everywhere. 

• UC Standard version built for UC applications and softphones from Avaya, Cisco, IBM, Skype and more 
• Dual-ear hi-fi stereo for those who want a richer, more immersive audio experience 
• Ideal for all-day use, long conference calls, and listening to multi-media 
• Available in dual-ear hi-fi stereo (Blackwire 520) or single-ear mono (Blackwire 510) 
• Smart Sensor™technology lets you answer a call by simply putting on the headset 
• One-touch call answer/end, vol +/-, and mute 
• Inline indicator lights and user friendly audio alerts the user to connection, mute and volume status 
• Dynamic EQ automatically adjusts audio settings between voice calls and music 
• PC wideband audio with noise-canceling microphones for high-quality PC telephony 
• Digital Signal Processing (DSP) provides natural voice sound 
• SoundGuard technology provides protection against audio spikes 
• Ultra-soft leatherette ear cushions and lightweight headband provide all day comfort 
• Take it on the go, with folding ear cushions and included carrying case 
• Plantronics Spokessoftware provides added benefits: