Radio Frequency HeadphoneDescription1) 3 channel RF wireless stereo headphone for Car2) 3 channel UHF wireless stereo transmitter for car3) Distance from 10m to 100m up to customer requirements4) Active noise reduction system 5) Auto mute and auto tuning function6) Auto power on/off function for transmitter7) Double PLL system8) Many headphones can be used simultaneously with a transmitterSpecifications1) System: UHF/RF2) Carrier frequency: 914 : 914.5 : 915MHz3) S/N ratio: 75dB(minimum)4) Mode: stereo5) Channel separation: 35dB(minimum)6) Distortion: 1%(maximum)7) Frequency response: 30 - 20,000Hz8) Power supply of transmitter: DC12V-24V 150mA9) Power supply of headphone: 2 x AAA BatteriesAccessories1) Audio cable2) AAA Batteries3) Guarantee letter