TOPEPOP Bluetooth Car Kit V4.1 Handsfree Car Bluetooth Music Receiver Built in Mic with USB and 3.5mm Audio Cable for Smartphones Digital Products with Bluetooth Function Bluetooth connects to smartphone, Aux-In connects to car stereo, Keep the bluetooth receiver power on. Routes calls and music from a smartphone through car speakers,Seamlessly switches between calls and music. Connect two phones at the same time High quality PC & fine sand blasting aluminum material, imported chips, high performance data line to ensure a good signal. Bluetooth 4.1 technology, The effective distance of 10 meters. mini size design, Convenient to carry.Compatible with most of bluetooth devices. Enjoy your favorite music from phone/tablet: Scream audio through 3.5mm input in car stereo, such as music, GPS voice navigation, and podcast