Specifications: 1.Voltage: 12-24V 2.Frequency Range:87.5-108MHZ 3.Bluetooth Version:V5.0 4.Product Size: 33.7*80.0mm 5.Product Weight:37g(NW)/73(GW) Features: 1.Hands-Free Call 2.Dual USB ChargeMeanwhile 3. Display The Voltage Functions: 1. Quick Charge 3.0 (DC3.5-6.5V/3A 6.5-9V/2A 9-12V/1.5A) 2. Support USB Flash Drive(only FAT32 format) max 64GB Package Include: 1 x FM Transimitter 1 x Manul How To Use The Device?--All Models Can Follow This. 1.Start you car and set a blank frequency WITHOUT any show on your car radio 2.Insert the device into your car cigarette light, and set the same frequency as your car radio 3.Turn on bluetooth of your phone and search the device named"C57" to connect it 4.Now you can listen music from your phone app or U Disk, make hands-free call, navigate and charge your electronic devices. Dual USB Port Charge 1.One support 5V/1.0A charge, meanwhile it can readU-Disk(only FAT32 format) which max 64GB 2.One support quick 3.0 charge(DC3.5-6.5V/3A 6.5-9V/2A 9-12V/1.5A)