... optional 3.Support folder switch 4.Memory function Car MP3 FM transmitter AD-658 features:Built-in Flash memory,1-4GB optionalBuilt ... original Samsung flash chip,high quality and strong,stable car FM transmitterWith infrared remote control,choose the song/frequency directly Dimension ... or use the controller to selectSNR85 DBHAR distortion≤0.05%(FM<0.1%)Working temperature-5°C-40°CAvailable distance<5M ...