【NOT for Cell phones and Computers】: ONLY COMPATIBLE with Yealink T19P T20P T21P T22P T26P T28P T41P T23G T32G T38G T40G T42S T46S T48S Avaya 1608 1616 9608G 9611G 9620 9630 9640 9641G 9650 J139 J169 Grandsteam GXP 1400 1405 1610 1615 1620 1630 2000 2120 2124 2135 2170 280 285 GXV 3005 3006 3240 3275 Snom 300 320 360 710 821 870 Panasonic KXT 2260 7220 7330 7420 7433 7665 7740 Zultys ZIP 36G 37G 33i 35i AltiGen IP805 Aastra 6737i and more deskphones listed in description. | CRYSTAL CLEAR CHAT: Wideband Sound RJ9 Telephone Headset with microphone compatible with Yealink Avaya landline phones enables excellent sound quality for natural listening experience, features Noise Cancelling Microphone to reduce background noise, Acoustic Shock Protection Circuit to protect your hearing. | MOST COMFORT HEADSET: Super lightweight wired Hands-free RJ9 office Phone Headset compatible with Grandstream Panasonic Snom Desk Phones with adjustable headband to fit all head sizes, high quality and soft leatherette ear cushion enhance all-day wearing comfort. Professional Mic Mute/Volume Control built in. | ULTRA DURABLE: Precision design, quality plastics, unibody headband construction, superior quality microphone makes this call center phone headset with RJ9 jack sturdier and more durable. Compete with Plantronics or Jabra heavy duty Telephone Headphone for Call Center, Hospital, Office, Home, Insurance, Business, School, Bank, Telephone Counselling Services. | 1-YEAR WARRANTY & COMPATIBILITY NOTES: 45 DAYS MONEY BACK GUARANTEE & 1 YEAR WARRANTY. ONLY COMPATIBLE WITH SOME SPECIFIC PHONE MODELS LISTED IN DESCRIPTION (include but not limited). NOT for Smartphones and Computers. For Other Phones, Pls contact us for Compatibility Guide or Advice.