SUNDELY&reg; Call Service Headset with Adjustable Boom Volume Control Mic 4-pin RJ9 Modular Connector for Telephone /IP Phone Nortel Networks (Northern Telecom) Packet 8 Panasonic Polycom Safecom ShoreTel Call Service Headset with Adjustable Boom Mic 4-pin RJ9 Modular Connector for Telephone /IP Phone 4-pin RJ9 Modular Connector, Adjustable Boom Mic, Volume control Nortel Networks (Northern Telecom) Meridian PBX: M3903, M3904, M3905, M2216, M2008, M2616, Meridian Norstar M7208, M7310, M7324, M7900, M9009, M9516, T7208, T7316, T7316E, Nortel 3903, 3904, 3905, Meridian Option M3110, 3310, 3820, BT Converse 220, 225, 300, 320, 325, 420, 425, 1100, 1200, 1300, 1400, Paragon 450, I2002, i2004 (not compatible with i2400 phase II and i2004 POE phones), 1210, 1220, 1230, 2465, 2564, NT8B20, NT8B30, NT8B40, NT8B50, NTZK23AA, AB (M2216), ACDI Packet 8 Phones 6753i, 6755i, 6757i, Polycom SoundPoint IP Phone Series, 300, 301, 335, 500 (rev. 5 or later), 550, 600, 601, 650 POLYCOM IP300, IP301, IP430, IP450, IP500, IP501, IP600 &IP601 IP Phones, Safecom SDSIP-500IP, SIP Phones, ShoreTel Phone:&lt;/b&gt; IP100, IP212K, IP230, IP265, IP530, IP560, IP560G, IP565