Blue Tooth Car Adapter Adjustable FM frequency 87.5 108 MHz: Convert any car stereo into a Bluetooth music source and stream wirelessly by tuning to an unused FM channel. calls with clear audio: Builtin microphone and speakerphone let you answer or reject calls easily while keeping focus on the road. No charging required: Simply plug the adapter into your car's integrated card slot; enjoy music streaming and hands calling without charging cables or extra wiring. Advanced music technology: Automatically identifies and delivers optimized audio from TF cards of various brands for clear, quality sound with plugandplay convenience. Use scenarios Daily commute: Enjoy wireless music and hands calls during your regular drive without changing your setup. Road trips: Load playlists onto TF cards and play them through the car stereo for uninterrupted offline listening. Rideshare or taxi operations: Add Bluetooth streaming and hands calling to an older vehicle, improving passenger experience without extra wiring.