... Distortion: Less than 1%10. Sensitivity: 115dB ± 3dB/mwat1KHz11. Omni directional microphone12. Frequency response: 100-3000Hz13. Impedance: 22000 ohm14. Sensitivity:-36dB ... , 5235, 5240, 5550 IP NEC: Electra Elite DTerm, Series E, Models DTU-8, DTU-8D, DTU-16, DTU-16D, ... IP560G, IP565 Siemens/ROLM: Optiset E Series with CA or HA option modules Optiset E Advance Optiset Advance Plus+ Headset Adapter ...