The HD 400S is a closed back headset featuring a one-button smart remote conveniently located on the cable, allowing music and call control. The sturdy folding design makes these headphones durable and compact enough to be taken anywhere. Sennheiser proprietary dynamic drivers deliver an extended smooth response with exceptional clarity and dynamic bass. Precision German engineering ensures excellent audio clarity, so you will hear every detail of your music. One button inline smart Remote makes it convenient to play and pause music and take calls without needing to fumble with your phone. Lightweight foldable design allows for easy storage making the headphone easy to carry anywhere. Secure over-ear fit provides excellent reduction of ambient noise, so you can relax and focus on the music.