2.5MM TELEPHONE HEADSET (for landline and cordless phones only): COMPATIBLE WITH AT&T Vtech Panasonic Uniden RCA Cisco SPA Grandstream Zultys Gigaset Office landline and most cordless dect phones with standard 2.5mm headset jack. For compatibility list in details, please check description below (include but not limited). NOTE: THIS PHONE HEADSET DOES NOT BE USED FOR CELL PHONES AND COMPUTERS. | CRYSTAL CLEAR CALLS: Mono 2.5MM landline phone headset with 330°adjustable, flexible microphone supports your wearing preferences and delivers optimal clear voice. Noise-cancelling mic reduces background noise. Acoustic Shock Protection Circuit protects your hearing from fatigue and loss. | LIGHTWEIGHT AND COMFORTABLE: Wired office headset with adjustable and flexible headband fits all head size perfectly and wear on firmly. Ultra lightweight telephone headset equipped with soft leatherette ear cushion improves the comfort of all-day wearing. | EASY TO USE: Directly plug and use, no additional amplifiers or adapters required. The business telephone headset has inline volume control and mute switch to provide convenience for calls, which is an ideal choice for call center services, teleconferences, telemarketing, homes and offices. | ULTRA DURABLE & 2 YEARS WARRANTY: 45 days full refund and 2 years warranty. DON'T BUY IT FOR COMPUTERS AND CELL PHONES. Professional structural design with solid cord ensures this office phone headset more durable.