Plantronics Blackwire C620 Plantronics Blackwire headset. Professional grade wideband audio optimized for PC communication environments where frequent softphone conference calls take place. Noise-canceling microphone limits outside noise interruptions, ensuring excellent audio quality and easing listener fatigue. Echo cancellation for full-duplex speakerphones when both the microphone and speaker are on at the same time. We only accept return within 115 days.