?2-YEAR WARRANTY & COMPATIBILITY NOTES?: We offer 45 days money back & 24-month worry-free guarantee. THIS HEADSET DOESN’T WORK FOR SMARTPHONES AND COMPUTERS. ONLY COMPATIBLE with some specific phone models listed in description (include but not limited). For Other Landline Phones, Pls contact us for Compatibility Guide or Advice. ?QUICK DISCONNECT CORD & SUPER DURABLE?: Quick Disconnect(QD) feature enables you to walk away from the desk without taking headset off. Precision design, quality plastics, unibody headband construction, flexible mic boom makes this office phone headset with RJ9 jack sturdier and more durable. Ideal for Call Center, Office, Home, Hospital, Insurance, Business, School, Bank, Telephone Counselling Services. ?CRYSTAL CLEAR CHAT?: High sound quality RJ9 Call Center VoIP Phone Headset with Microphone enables excellent sound quality for natural listening experience, features Noise Cancelling Microphone to reduce background noise, Acoustic Shock Protection Circuit to protect your hearing. Less noise, Clearer voice. ?ULTRA COMFORT?: Ultra lightweight wired Hands-free RJ9 Telephone Headset compatible with Avaya Zultys Meridian Digium Aspire Dterm 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. Compete with Jabra business-grade Telephone Headphones. ?RJ9 JACK HEADSET COMPATIBILITY?: See Compatible VoIP Phone List in Description. Direct connect over the head landline telephone headsets with microphone, COMPATIBLE with Plantronics ShoreTel Mitel NEC Allworx Nortel Norstar Aastra Toshiba Gigaset InterTel Siemens, Polycom: SoundPoint 250 300 301 335 430 450 500 501 550 560 600 601 650 670 CX300 CX500 CX600 CX700 VoIP VVX300 VVX310 VVX311 VVX330 VVX400 VVX410 VVX411 VVX500 VVX600 and more specific landline phone models listed in description.