VXi 203055 UC ProSet 21 V DC Over-the-Head Binaural Headset with DC N/C Microphone Superior noise canceling eliminates background noise (up to 89 percent) and improves communication. Wideband audio (HD Voice) provides clearer conversations and greater productivity. Hearing protection suppresses sudden and unexpected sound spikes. High quality durability stands up to all-day, every-day use. Requires V-type QD lower cord (available separately) to connect to your phone.