Bluetooth 4.0 In-Car Adapter FM Transmitter with USB Charging,Sitlos Portable Wireless Music Controls & Hands-Free Calling Car Kit for iPhone,Samsung,LG,HTC,Nexus,Sony Android Smartphone-Black

it's perfect for my requirement, but the Bluetooth pairing sometimes has a little problem. I only use it to pair to my cell phone, but every time I turn on this transmitter, it is not always pair to my phone successfully.