The UR40 delivers digital quality sound in an ultra-lightweight design for listeners on-the-go. The UR40 features dynamic elements for a wide frequency response from 15-22,000 Hz. Computer optimized neodymium iron boron rare earth magnet structures enable the UR40 to deliver greater volume, even with low-voltage portable devices. Oxygen-free copper voice coils improve signal transmission and conduction for cleaner, clearer sound. With its hybrid design, the UR40 combines the best of closed-style and open-style headphone. Closed leatherette ear cushions form a light seal around the ears, enhancing bass frequencies. Screened ear cups provide an open, hear-through sound that lets listeners stay in touch with the world around them. The result is a full frequency, clean sound that turns any recording into a "live" performance.