... plug this modular plug into the headset jack on your phone (phone must be headset-ready, see list below) Superior sound ... phase II and i2004 POE phones) Alcatel-Lucent: 4004, 4020, 4022, 4035, 4037 Telephones AltiGen phone Models: 500, 510, 600, 705, 710 ... , 720 Ascom: Berkshire 200, 400, 600, 800, SD30, MR30, MR51, MR61 AVAYA / Lucent: 6402D ...