Noise cancellation headphone

noise cancellationheadphone feature: 1. Active noise cancelling technology to enhance the power of noise filtering. 2. Block the external noise to offer a superb listening experience. 3. Headphone foldable and cable detachable design, convenient for traveling users especially for users in noisyenvironment like subway, airline, highway, etc. 4. Noise cancelling and common wired headphone available (only for JH-301B) 5. Driver unit: 40mm dynamic speakers 6. Impedance : 32Ω±10% 7. Frequency response : 20Hz - 20KHz 8. Reduction level: >16dB at 300Hz 9. Sensitivity: 102 dBμv at 300Hz 10. Cord length: 1. 2m 11. Plug: 3. 5mm stereo plug 12. Power requirement: 2 × AAA batteries(not included)