ULTRA DURABLE and MOST COMFORT HEADSET with SUPERB SOUND QUALITY, Compete with Plantronics or Jabra high-grade Headsets for Call Center, Telemarketing Office and Cordless DECT Phone. COMPATIBLE PHONE LIST: (Include but not limited) Cisco Linksys: CIT200, CIT300, CIT310, CIT400 SPA921, SPA922, SPA941, SPA942, SPA962 Cisco SPA: 303, 501G, 502G, 504G, 508G, 509G, 525G 512G 514G,525G2 Cisco: 7985 Unified IP phones Polycom: IP320, IP321, IP330, IP331, SoundPoint Pro SE-220 SE-225 Grandstream: GXP-2010, GXP-2020, GXP-2100, GXP-2110, GXP-2120, GXP-280, GXP-285, BT200, BT201 GXP-2000(Version 1.0 higher with 2.5mm Headset Socket) Panasonic: KX-NT136, KX-NT343, KX-NT346, KX-NT366 ,KX-T 7603, KX-T 7625, KX-T 7630, KX-T7633, KX-T 7636, KX-T 7730, KX-T 7735 KX-TG6071B, KX-TG6072B, KX-TG6073B, KX-TG6074B,KX-TCA60 Gigaset: C610 IP, C620H Zultys Technologies: ZIP 4x4, ZIP 4x5 IP Phones Plus Many Many Cordless Phones with standard 2.5mm Headset jack from brands below Uniden ClearSounds EnGenius Thomson Vtech Audioline Toshiba Ameriphone Sanyo Philips Teledex Novelty Phones Aria Southwestern Bell Karcher Serene Innovations Aastra Telecom Siemens Bellsouth Vodavi Cortelco Ameritech Sharp LogicMark CLEAR SOUNDS Muraphone Midland Verizon SBC NEC IBM Motorola Coby Electronics GE Pacific Bell Sylvania Binatone Conair Lenmar RCA MCE ITT Clarity 5.8GHz 900MHz Arama Wantek Wired Telephone Headset Mono with Noise Canceling Mic Volume Mute for Cisco Linksys SPA Polycom Grandstream Panasonic Zultys Gigaset Office IP and Cordless Dect Phones with 2.5mm Jack (A602CP)