Poly EncorePro HW520 is a dual ear (binaural) over-the-head only headset with soft ear cushions that a designed for the typical office worker.  HW520 has a unique design with an ergonomic fit that is durable, lightweight, and comfortable for all day use. The noise canceling technology and high-quality audio ensures more focused and private calls, so conversations will be heard clearly with fewer missed words. The design of the Poly EncorePro HW520 has metal joints that deliver durability and reliability, and a flexible microphone with visual positioning guides for precise positions. Included comes Poly DA85, an USB-A & USB-C adapter that allows the attachment of the Poly HW520 QD to the computer. It offers in-line one-touch controls for volume, mute and hold

Key Features:

• Noise canceling microphone
• Telecoil Hearing Aid Compatible
• Visual and tactile positioning guides enable precise and quick microphone positioning
• Wideband audio delivers richer, clearer conversations, while SoundGuard technology protects from noise spikes and listening fatigue
• Adjustable fit enhances for wearing comfort
• UC platform compatible
• DA 85 built-in USB-A and USB-C connectors, with Call answer/end, mute and volume controls
• 1-year Poly warranty

For more detail information see Poly HW520, DA85 datasheet