What is important in FM transmitters that the radio dial starts at 87.5 MHz, as it will save you with this "universal frequency" frequent readjustment of the frequency. It is very important also to match the volume of the two devices (transmitter and radio) to each other. Is the transmitter set to silent, you have to turn on the radio too much and it roars. Is the transmitter too loud, the music is distorted and overdriven over. So quiet experiment to the settings! Amsonsten I was also the "little brother" of this unit (mumbi Car FM Transmitter / MP3 Player + Remote Control and SD MMC Slot & USB port for 9.90) sounded moderately totally satisfied, but after a short time, always so stupid deficiencies presented there a (barbs the connector for the cigarette lighter broke off, USB port broke off and said goodbye inside the unit). Thanks to Amazon and prompt refund That was no problem, but I would like something more permanent! Sign up again, although I can not say what. At least stable sees this Transmitter ever made! Therefore, only by 5 star!