description： the transmitter can be widely compatible with multi-media such as tv,pc,dvd,cd,vcd,mp3 and other electronic products with audio output plugs.good quality of the sound and be effective with over 30m and the sound signal can penetrate barriers like walls and objects without the angle limitation 。 tv-accompanying: working frequency:72--75mhz you can enjoy the tv program freely without disturbing others by using wireless headphone. the receiver has two frequencies to avoid the disturb of the same frequency efficiently. you may use two transmitters in one space to enjoy two different programs. technology parameter transmitter receiver working frequency:72--75mhz working frequency:71--76mhz power supply: dc 3v power supply: dc 3v transmit distance: ≥ 30m load:32Ω input signal :max500mv signal/noise ratio: ≥ 50db input impedance:10kΩ integrated frequency response