... modular plug into the headset jack on your phone (phone must be headset-ready, see list below ... , 5420 5610, 5620 DT1, DT3, DT5 Cable & Wireless: CWB 100H, CWB 200H, CWB 500, CWB 600 Comdial ... Dialogue 4186, MD110 ESI: ESI-48-Key IP Feature Phone and 48-Key Digital Feature Phones General ... 500 Packet8 Phones: 6753i, 6755i, 6757i Polycom: SoundPoint IP Phone Series, Models 300, 500 (rev. 5 or later), ...