Specifications: 1) Operating distance: up to 30 meters 2) Frequency range: 20-1,500Hz 3) Working current: 45mA ? 10mA 4) Operating frequency: labeled on the unit 5) Output current: 100mA max (according to different models) 6) Preset frequency station: 87.7, 87.9, 88.1, 88.3, 88.5, 88.7, 88.9 7) High quality music comes from the acoustics when connecting with the USB flash disk and MP3 directly. It has seven channels for choosing. It can take the convenient, fashion, and superior for people 8) This incredible new product is adopted with 3D sound coding technology, which maintains the hi-fi effects of MP3, MD, CD and TV 9) It has been developed from frequency phase lock loop ethnology, which ensures stable frequency radiation while functioning at a distance of up to 30 meters with no dead areas, it operates through your automobile audio sounding equipment so that you can still enjoy hi-fi music