Infrared wireless stereo headphone(Dual Channel) * Carrier frequency: A source: 2.8MHz(right); 2.3MHz(left) B source: 3.8MHz(right); 3.2MHz(left) * Monitor function--you can silence the music from headphone to listen outside * Compatible with all vehicle AV applications * Auto mute and auto power off function * Comfortable wearing with adjustalbe headband * Personal volume control * Effective range up to 8 metres * S/N ratio: ≥60dB * Speaker: 40mm mylar * Power supply:Requires 2xAAA batteries