DESC: Home and portable audio take on fresh life with quality headphones, and Koss's lightweight, closed-ear UR40 is designed to keep outside noises out and headphone sound in--perfect for use in busses and libraries alike. With its extended frequency range of 15 to 22,000 Hz, you'll never miss a single bass note or want for high-frequency splash or shimmer.The UR40's titanium driver elements ensure taut low end and clear treble, while its collapsible headband design further lends it to portable applications and protects the headphone when not in use. The headphone comes with a four-foot, dual-entry cord and a .25-inch stereo adapter for use with hi-fi components.