Function and range: The Blue Tooth Car Adapter converts any car stereo into a Bluetooth speaker by transmitting audio via FM. It offers an adjustable frequency from 87.5 to 108 MHz for wireless music streaming. Hands calls: Builtin microphone and speakerphone let you answer or reject calls easily. Stay focused on the road while enjoying clear calls and simple dialing. Connectivity and quality: Bluetooth 5.3 enables faster pairing, clearer sound, and reliable performance. Broad compatibility with mobile phones ensures easy integration with your existing devices. Nocharging design: No separate charger required. Simply plug the Blue Tooth Car Adapter into your car's integrated card slot and enjoy music streaming and hands calls without wiring or charging. Design and compatibility: Compact form factor for easy placement and use. Compatible with a wide range of car stereo systems by providing Bluetooth streaming through FM transmission. Use scenarios: Daily commute: Stream your phone's music through the car stereo while keeping hands for calls. Road trips: Enjoy uninterrupted music and clear hands conversations during long drives. Rental or older cars: Add Bluetooth streaming to vehicles without builtin Bluetooth by using the FM transmission method.