Plantronics EncorePro HW520 Stereo Headset The Plantronics EncorePro 520 is the binaural version of the all-new 510 design, covering both ears to provide greater focus and concentration by blocking background noise. The 520 also has soft ear cushions for all-day wearing comfort, metal joints that deliver durability and reliability, and a flexible mic with visual and tactile positioning guides for precise positioning and clearer conversations.