Fangrui Product Details Enjoy Wireless Audio - 2 In 1 Bt 5.4 Wireless Receiver Transmitter. Receive/transmit, One Click Switching. Kind Reminder: When Using The Receive And Transmit Functions, You Can Only Choose Between Two Options. Receiving Mode - Connect To Speakers, Receive Bluetooth Signals, And Play Music Wirelessly. When The Receiving Mode, The Indicator Light Is Blue. Transmit Mode - Connect The Audio Output Port Of The Device And Play Music Wirelessly Through Paired Wireless Headphones And Bluetooth Speakers. Long Battery Life With Built-in Battery - Built In 200mah Rechargeable Lithium Battery, Type-c Interface For Charging, Real-time Battery Display,and Durability. Receiving Mode: New Experience Of Wired To Wireless Music - Connect To Wired Speakers, Break Space Limitations, And Enjoy Wireless Fun. Handsfree Call, Freeing Hands - Built In Microphone For Clear Communication, Keep Hands Off The Steering Wheel For Safer Driving. Make The Car Equipped With Bluetooth,wireless Connection, And Enjoy Mobile Music, Voice C