Transforms any audio signal into frequency modulated signal and wirelessly send to any FM stereo system without remodel. Car-Using Set the car FM receiver to any frequency from FM88.0 to FM108.8 and adjust the emitter the same number. Or use the auto search function of FM receiver to search the marked frequency of WT-601. Household-using Set the HI-FI FM receiver to any frequency from FM88.0 to FM108.8 and adjust the emitter the same number. Or use the auto search function of FM receiver to search the marked frequency of WT-601. This emitter is compact , fashionable. The Hi-Fi quality is CD-near. Good value for money .Give you an FM radio. In car-using you can share your wireless music signal with several cars nearby, and in household using you can listen to MP3 music that play in the FM receiver. PLL technique guarantees the frequency modulated signal emits steadily. The longest transmitting distance can reach 20 meters which ensures you enjoy HI-FI music either at home or in your car.