Dual connectivity: connect up to 2 Bluetooth-enabled devices to the receiver and listen to music or answer calls from both devices. It is compatible with Bluetooth V1.2 / 2.0 / 2.1 / 3.0 / 4.0 / 4.1 / 4.2 and can effectively avoid unstable connection problems. LED light with 7 colours: the LED light remains on permanently after successful Bluetooth pairing. Short press to change the colour. It allows you to easily see during the night and will make the interior layout of your car cooler and more appealing. Google Siri & Hands-Free Calling: Work with intelligent Siri faster and more comfortably with which you can ask questions, make calls and much more. HVAC noise cancelling technology also provides clearer, quieter hands-free calls for safer and safer driving when using this Bluetooth radio transmitter. Quick charging and 2 USB ports: this FM transmitter supports charging 2 devices simultaneously. The QC3.0 port can charge one phone to 80% in 35 minutes, and the other USB charging port (5V/2.4A) also acts as a U disk port. Unique EQ modes: the Bluetooth car adapter supports 4 music playback modes: AUX / Bluetooth / USB / TF card. Besides, you can set music from USB drive and TF card to normal, classic, pop, rock and jazz EQ style. CVC and anti-static technology ensures full duplex sound quality and guarantees you lossless music in the car. Product operating instructions: Open Bluetooth on your phone and search for the pairing name "Carkit". Click the pairing name to connect to Bluetooth. When a call comes in, you can briefly press the phone button to answer/hang up/long press to reject. Double click to reset the call. After connecting the call, you can press and hold the mode button to switch the private answer. Note: Only the last call sent in the call list can be played. Frequency adjustment:After turning on, press and hold the up and down tracks to enter the transmission frequency and adjust the addition and subtraction. Note: Long press up and down song & FM increase and decrease quickly, short press for fine tuning. Please note: There is a built-in antenna for the product. Therefore, avoid using the station frequency with strong signal to achieve a better sound effect. The method of operating the Bluetooth may vary due to the different phones used. Some phones may not support automatic connection if they are turned on after the power failure. If so, please connect it by hand. This product is compatible with more than 95% of phones on the market, but some are still not compatible. Please be aware of this when purchasing our product. The volume should be appropriate during the call to avoid interfering with the other participant. Do not drop the product to avoid surface damage or drops. Package includes: 1 x Bluetooth FM transmitter