Superlux HMD685A, Single-Ear Intercom Headset, For IS103 Intercom System, Closed, Dynamic, Noise isolation, Colour: Black@+*Technical data Headset:*@+@+, Frequency range: 20 - 20000 Hz, Impedance: 400 Ohm, Sensitivity: 96 dB SPL @ 1 kHz, 1 mW Max., 100 mW input power@+*Technical data Microphone:*@+@+, Dynamic, Characteristics: kidney, Frequency range: 50 - 15000 Hz, Impedance: 200 Ohm, -64 dBV / Pa (0.6 mV / Pa) @ 1 kHz, 1.5 Meter connection cable with 4 pin XLR female connector