Mpow Bluetooth 4.0 FM Transmitter, Wireless Bluetooth Car Adapter with Built-in Mic for Handsfree Calls and Voice Assistant, Bluetooth Car Kits with 330 Degree Rotatable Head for Easy Control ADVANCED BLUETOOTH 4.0 FM TRANSMITTER: Adopting Bluetooth 4.0 chip for getting higher quality audio sound than the Bluetooth 3.0 version, both in playing music and answering phone calls. ADJUSTABLE & FLEXIBLE CAR ADAPTER: The high quality neck, combined with the 330 degree rotatable head can be adjusted to arbitrary angle to suit your perfect view.Mpow also has a 2.1A USB output for charging your other device with ease. SIRI FUNCTION: We always keep pace with times, that's why we add the Siri function to the Mpow streambot Bluetooth transmitter, thus you can activate the voice software by clicking the sided button. TOP-NOTCHED QUALITY: As for the craftsmanship, We have been following through the process of the design, manufacture production for nearly two years .We select the industry-level components for Mpow Flex ,thus a higher quality Flex is born ! AUTO-SEARCH FUNCTION: You can press the "FM Tuner -" and "FM Tuner +" button on the fm transmitter at the same time for about 3 seconds to auto-search a blank station.