Function usb sd up to 32gb to play music from pendrives or SD cards.
Function fm: to pair with the radio station of the car.
Frequency range: MHZ.
Charging function: comes with a charger 3 in 1 for devices with usb-C / Lightning / Micro usb inputs.
The usb port also supports load of 2.1A.
Memory: the device saves the latest radio station configured.
Also retakes the latest music played by usb
Buttons: Volume control, Previous/Next.