Sony Premium Powerful Lightweight Extra Bass Stereo Headphones (Black) 30mm Neodymium Dynamic Dome Drivers - Specially designed, powerful drivers deliver deep and powerful bass that perfectly complements today's popular music genres 5 to 22,000 Hz Frequency Response - The headphones use supra-aural closed-back 30mm neodymium dynamic dome drivers to deliver a frequency response of 5 to 22,000 Hz into a 24 load with a sensitivity of 98 dB/mW. Sealed Acoustic Design for Isolation - A tightly sealed acoustic design allows for a high level of sound isolation which aides in the reproduction of powerful and extended bass sound Swivel-Fold Earcups - Slim in stature with swivel-fold earpads, Sony Extra Bass headphones are lightweight when worn, yet easily stow away in a backpack or book bag when on the go Pressure-Relieving Urethane Foam Fit - Seamless, noise isolating ear pads use pressure relieving urethane foam for not only an outstanding fit, but also reduced ambient noise