... require no amplifier! They plug directly into your headset-ready telephone! What's in the box: Headset shown above, plus ... Phone and 48-Key Digital Feature Phones General Electric: GE Telephone Model 2-9451, 2-9490 GrandStream IP Phones: Budgetone 101 ... 2564 NT8B20, NT8B30, NT8B40, NT8B50, NTZK23AA, NTZKAB: (M2216): ACDI Orchid: DBT 2000, DBT 3000 Plantronics: A100, S10, S11, S50, T10, T20, T50, T100 ...