Overview: The HD 400S features a one-button smart remote conveniently located on the cable which allows you to control music and take calls with ease. The sturdy folding design makes these headphones durable and compact enough to be taken anywhere. Sennheiser dynamic drivers deliver a well-extended sound response with dynamic bass. Features: -Renowned Sennheiser sound quality for a unique listening experience -Built-in microphone and remote for call and music control -Closed-back around-ear headphones reduce unwanted background noise for your comfort -Lightweight, foldable headphones for easy on-the-go storage Technical Data: -Impedance 18 ohms -Frequency response (Microphone) 100 – 10 000 Hz (-10 dB) -Frequency response (Headphones) 18–20 000 Hz (-10 dB) -Sound pressure level (SPL) 120dB (1kHz/1Vrms) -THD, total harmonic distortion less than 0.5% (1kHz/100dB) -Ear coupling (over-ear) -Jack plug 3.5mm angled -Cable length 1.4m -Transducer principle dynamic -Weight 217g -Pick-up pattern omnidirectional -Microphone sensitivity 44dbV/Pa -Acoustics Closed -Sensitivity 120 dB SPL at 1 kHz, 1V RMS What's in the box HD 400S around-ear headphones RCS 400 detachable single-sided cable with 1-button remote and 3.5 mm angled plug