1) Infrared wireless stereo headphone for car audio systems 2) Single channel for one car audio source 3) Folding Design 4) Compatible with all vehicle AV applications 5) Auto mute and auto power off function available for headphones 6) Effective range up to 10 meters 7) Ultralight weight design for comfortable wearing with adjustalbe headband 8) Numbers of headphones can be used simultaneously in the car 9) Personal volume control Specifications: 1) Carrier frequency: 2.8MHz(right); 2.3 MHz(left) 2) Speaker: 30mm mylar 3) Cone impedance: 32Ω± 15% 4) Effective range (maximum): About 10 meters 5) Audio model: Stereo 6) S/N ratio: ≥60dB 7) Channel separation: ≥40dB 8) Frequency response: 30 ~ 20, 000Hz 9) Power supply: 2 AAA battery