Sandberg USB RJ9 11 Headset Pro Stereo - Connects through a USB, RJ9 or RJ11 port and works immediately Earphone: Driver unit: 30 mm, Frequency range: 20 Hz 7 kHz (human voice filtered) Microphone: Type: 2.7 mm dia. electret condenser microphone, Direction: Uni-directional, Frequency Response: 50 Hz - 16 kHz, Sensitivity: -40 dB 3 dB Više informacija na linku