Feature: 1. Frequency: 863.1-863.5MHz 2. Frequency response: 20Hz-20KHz 3. Distortion: <0.5% 4. S/N Ration: >60dB 5. Separation: <30dB 6. Sensitivity: 2uV 7. The max output power: 480mV 8. The best receive range: 280 feet 9. The max receive range: 300 feet (100 meters) 10. Headphone's Power supply: 700mA Ni-MH rechargable batteries 11. Transmitter's Power supply: AC adaptor 12. The life time of recharge batteries: Can be recharged by 1200 times 13. Usage Time of recharged once: 16 hours 14. Automatic power off after 1.5 to 3 minutes of signal off Features Stereo high frequency wireless headphones of high and bass sound. High resistantly of interference. And adopt PLL function. Applicable with TV, DVD, DV, computer, MP3 and other electronic products with Audio output. Packing: Color box size: 321.7*216.7*136.5(mm) Carton box size: 452.4*427*327(mm) of 6pcs 6 units/carton box G. W: 7.1KG N. W: 6.3KG 2947 units/20FT 5898 units/40FT