WIDE COMPATIBILITY: 【NOT for Cell Phones and Computers】 This corded RJ9 office phone headset is ONLY Compatible with Some Specific Phone Models from Plantronics Avaya Northern Telecom ShoreTel Allworx NEC Toshiba Digium Zultys InterTel Nortel Norstar Meridian Aastra Packet8. SEE MORE COMPATIBLE PHONE MODEL LIST IN DESCRIPTION. | CRYSTAL CLEAR CALLS: Wideband sound call center landline 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. | ALL DAY COMFORT: Super lightweight mono telephone headset with super 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. | 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. | ULTRA DURABLE: Precision design, quality plastics, uni-body headband construction, high quality microphone makes this hands free RJ11 headset with microphone sturdier and more durable. Professional Mic Mute / Volume Control built in.