Plantronics Poly EncorePro 320 Stereo Headset - QD - Black Poly EncorePro 320 Stereo Headset - QD - Black Features Flexible noise-canceling microphone to tune out background noise. Voice-optimized frequency response for clearer conversations. SoundGuard acoustic limiting technology to protect against Acoustic Shock by limiting sounds to below 118dBA Proven reliability with Quick Disconnect (QD) tested to over 30,000 cycles. Fast and Free Shipping You're already purchasing the item. Why pay additional for shipping, especially slow shipping? We get your order shipped out within 1-business day and delivered to your doorstep as quickly as possible. Competitive Pricing With our dynamic pricing model, our prices are always competitive. Our prices are some of the lowest that you will find on the internet. Rest assured that you're getting a good deal when purchasing with us. 30-day Money Back Guarantee We are committed to making sure that you leave this transaction satisfied. If you're unhappy with the product for any reason, you may return it back for your money-back or a replacement within 30 days. No questions asked!