Features: 1) Invisibly connects with any TV, VCR, VCD, DVD or audio system 2) Operation distance: up to 15m with latest infrared wireless technology 3) Auto mute for headphone and built-in 40mm mylar speaker 4) The transmitter has dynamic LED display for input audio level 5) Active noise reduction system for crystal clear sound 6) Several headphones can be used simultaneously with one transmitter Specifications: 1) System: infrared light (850) 2) Carrier frequency: a) L channel: 2.3MHz b) R channel: 2.8MHz 3) Modulation: FM 4) Mode: stereo 5) S/N: >75dB 6) Channel separation: >35dB 7) Distortion: <1% 8) Frequency response: 30 - 20,000Hz 9) Power supply of transmitter: DC12V, 150mA 10) Power supply of headphone: 2 x AAA