This is the Plantronics HW710-YEA Yealink phone certified headset. Engineered just for the Yealink phone models.  Compatible with these Yealink models:

SIP-T19P, SIP-T20P, SIP-T21P, SIP-T22P, SIP-T23P, SIP-T23G, SIP-T26P, SIP-T27P, SIP-T28P, SIP-T29G, SIP-T32G, SIP-T38G, SIP-T40P, SIP-T40G, SIP-T41P, SIP-T41S, SIP-T42G, SIP-T42S, SIP-T46G, T46S, SIP-T48G, SIP-T48S SIP-T49G, SIP-T52S,SIP-T54S, SIP-T55A, SIP-T56A, SIP-T58A, SIP-T58V

Plantronics HW710-YEA has HD wideband audio and an superior noise canceling mic - removing any background noise. Designed with an over-the-head headband that keeps incoming sounds at a consistent and comfortable listening level.  Soft leatherette ear pads for all day comfort.  retractable microphone, so you can adjust to any postion you choose.

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Key Features

• Plantronics HW710-YEA package Includes Yealink certified RJ9 -10ft adapter cable - connects directly to the "headset" jack of your Yealink phone.

• High quality lightweight nylon composite materials

• Wideband Audio

• noise-canceling microphone

• Leatherette ear cushions provide hours of comfortable wear 

• Retractable microphone ensures precise microphone positioning

• Stylish, lightweight design enhances user experience

• Bendable boom for custom positioning

• 2-year warranty

For more detail information see Plantronics HW710 datasheet and Plantronics HW710 user manual

Optional accessories for the Plantronics HW710-YEA:

Plantronics Clothing Clip for SupraPlus, Encore Pro Headsets

Plantronics EncorePro HW710, HW291N Leatherette Ear Cushions

Plantronics EncorePro HW710, HW291N Foam Ear Cushions

Plantronics EncorePro Headband Support Pad