Wide Compatibility: 【NOT for Cell Phones and Computers】 This landline telephone headset is ONLY compatible with Some Specific Phone Models from Toshiba Digium Zultys InterTel Nortel Norstar Meridian Aastra Packet8. Compatible with Polycom VVX310 VVX410 VVX411 Plantronics S12 ShoreTel 230 Northern Telecom M3903 Allworx 9102 NEC DT400. SEE MORE COMPATIBLE PHONE LIST IN DESCRIPTION. | All Day Comfort: Super lightweight RJ9 office phone headset with ultra comfortable fit and adjustable headband to fit all head sizes, high quality and soft leatherette ear cushion enhance all-day wearing comfort. Compete with Plantronics or Jabra heavy duty Headsets. | Crystal Clear Chat: Wideband sound RJ11 telephone headset enables a clear listening experience, built in high quality noise cancelling microphone to reduce background noise, acoustic shock protection circuit to protect your hearing. Less noise, Clearer voice. | Super Durable: Precision design, quality plastics, uni-body headband construction, high quality microphone makes this corded call center headset with microphone sturdier and more durable. Professional Mic Mute / Volume Control built in. | 2-Year Warranty: 45 days money-back & 24 months warranty. Ideal for Call Center, Telephone Counseling, Insurance, Hospitals, Banks, Business, Office and Home. ONLY works for some specific phones with RJ9 jack listed in description. NOT for Smartphones and Computers. For other phones, pls contact us for compatibility advice.