Compatibility& Warranty: The telephone headset with mic work for Yealink SIP-T19P, T20P, T21P, T22P, T23P,T26P, T27P,T28P, T29G, T32G, T38G, T41P, T42G, T46G Grandstream GXP1200,GXP1400,GXP1405,GXP1610,GXP1625,GXP2020,GXP2100,GXP2110,GXP2120,GXP2124,GXP2130,GXP2140, Snom 320, 360, 370, 710, 720, 760, 820, 821 Escene,Huawei Akuvox, Sangoma(including but not limited) with RJ9 headset port. And 2 Years Warranty is offered for phone headset. Pls feel free to contact with us for any questions. Hearing Protection: emaiker corded desk phone headset with RJ9 jack, compete with Plantronics or Jabra heavy duty Headsets for call centers and office, with built-in hearing protection circuit to protect users against acoustic injury and sudden sound burst, any sound above 118db is filtered out, this telephone headset for office landline phones is ideal to people who are on the call all day long, such as call center agent, home phone job, telemarketing insurance, customer services etc. Luxurious Comfort: Call centers &office lightweight over ear telephone headset, wired desk phone headset is comfortable enough to wear for an extended period of time, no pressure on your head even for long time wearing. And adjustable headband fits for different head sizes and and flexible goose neck microphone boom offers accurate talking position. Phone headset one ear can be worn on either side and you can still communicate with your colleague while wearing it. GREAT DURABILITY: High-end materials and durable structure ensure the telephone headset to withstand the constant demands of all-day use in busy environments. The built-in reinforced quick disconnect cord will protect desk phone headphone against office chair wheels, sharp objects on daily use. Stainless steel headband, superior quality speaker and noise cancelling microphone, reliable plastic parts make this call center landline headset durable enough even for 24/7 busy environment. HD Sound Quality: The microphone phone headset is the over-the-head style telephone headset with mic for landline phones which is made for office workers, SOHO, work from home or call center agents. Wide band audio technology with communication speaker frequency enable phone headset delivering more richer and natural sound, plus ultra noise cancelling microphone to filter out background noise for clear 2-way communication.Professional call audio solution offers natural and clear hearing.