Sennheiser HMD-301 Pro, Single-Ear Headphones, Closed, Circumaural, Impedance: 64 Ohms, Nominal sound pressure level: 108 ± 3 dB SPL / 1 V rms / 1 kHz, Frequency response: 60 -25000 Hz, Harmonic factor <0.1% at 1 kHz - 100 dB SPL, Rated power: 500 mW, Contact pressure: 6.0 N ± 0.75 N, Dynamic microphone, Characteristic: Hypercardioid, Near-field frequency range: 80 - 16000 Hz, Impedance: 300 Ohms, Output voltage 0.4 mV / Pa at 1 kHz, Weight: 319 g, Single-sided cable (cable not included), Includes wind and pop protection, Suitable optional cables: Article Nr. #448025# or Article Nr. #448028# (not included)