Jh-301 noise cancelling headphone Jh-301 noise cancelling headphone could offer you a private space far away from noise outside, which is popular nowadays for mp4, ipod, psp users in noisy environment like airline, subway, highway etc. 1. Active noise cancelling technology to enhance the power of noise filtering. 2. Block the external noise to offer a superb listening experience. 3. Foldable design, convenient for traveling users 4. Driver unit: 40mm dynamic speakers 5. Impedance : 32 ohm ía10% 6.Frequency response : 20hz - 20k hz 7. Reduction level:>12db at 300hz 8. Sensitivity: 102db at 300hz 11.Cord length: 1.5m 12.Plug: 3.5mm stereo plug 13.Power requirement: 2 íß aaa batteries Colorful paper box