Heavyweight sound intensity teams with an ultra-lightweight design to create the ultimate in on-the-go listening, the Koss UR40. With improved signal transmission and conduction for a clean and clear sound, these headphones will minimize mechanical distortion and ensure exceedingly accurate sound reproduction. Featuring a hybrid design, the UR40 integrate the best of closed and open style headphones. Closed leatherette ear cushions form a tight seal around the ears to enhance bass frequencies, while screened ear cups provide an open, hear-through sound that keeps you in tune with your surroundings. The result: a clean, full frequency, great sound that turns every recording into a "live" performance. At just over six ounces, the Koss UR40 headphones wear comfortably, store easily, and travel lightly. Titanium sound in a collapsible, lightweight package. Specifications: Frequency range: 15-22,000 Hz, impedance: 60 Ohms, Sensitivity: 98dB SPL