VicTsing Wireless in-Car Bluetooth FM Transmitter Radio Adapter Car Kit with Dual USB Car Charger for iPhone,Androidphone,Supoprt Siri Activation Upgrade Version. Activate Siri by long press the control knob. Pairing faster, lower power consumption, higher sound quality. The top USB port can also Read USB Disk. Charge Two Devices Simultaneously. Two USB Charging ports ( 5V/2.4A and 5V/1A ) allows you charge your cell phone and tablet simultaneously. Stable performance,fast charging, no heat emission. Exquisite Craftsmanship. Adopted high precision SMD crystal oscillator, this car FM transmitter has more stable performance and longer lifespan. Noise Cancellation. This Bluetooth FM transmitter with hand-free function is designed with anti- interference processing. you can enjoy music or hand-free conversation through this gadget without generating annoyed electric current sound. Humanized Design. Built-in 3.5mm audio interface allows you play music from unsupported Bluetooth devices such as Mp3, Mp4, and other old type cell phones.