1) PLL technology 2) multi-directional transmission 3) frequency: 863.1MHz-863.5MHz or 912.5MHz-914.5MHz. 4) frequency range: 20Hz ~ 20KHz 5) distortion: <=0.5% 6) S/N Ration: > 60 dB 7) frequency range: 20Hz ~ 20KHz 8) R/L channel separation: >30dB 9) transmission range: 100 meters 10) power supply (transmitter): DC12V 11) power supply (headphone): 700mA/H rechargeable Ni-MH battery Feature: 1. Ultra-high frequency, high fidelity 2. Ultra-low distortion 3. Transimission through walls, floors, ceiling etc. With ease 4. Strong stereo sound 5. Strong anti-disrupption capability 6. High power output 7. Low FCC 8. Stable performance 9. Designed for EU&US markets 10. Simple&elegant look widely applicable to PC, TV, DVD VCD, MP3, MP4 and other major audio sources