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 colors: The LED light remains on permanently after successful Bluetooth pairing. Short press to change the color. It allows you to easily see during the night and enhances the interior appearance of your car. Google Assistant & Siri & Hands-Free Calling: Work with intelligent voice assistants like Siri and Google Assistant for faster and more convenient operation, including making calls and asking questions. CVC noise cancelling technology provides clearer, quieter hands-free calls for 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 functions as a USB drive port. Unique EQ modes: The Bluetooth car adapter supports 4 music playback modes: AUX / Bluetooth / USB / TF card. You can play music from a USB drive or TF card and select EQ settings including normal, classic, pop, rock, and jazz. CVC and anti-static technology ensure full duplex sound quality and deliver high-quality audio 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, briefly press the phone button to answer or end the call; long press to reject. Double click to redial the last call. After connecting the call, press and hold the mode button to switch audio output. Note: Only the last call in the call list can be redialed. Frequency adjustment: After turning on, press and hold the next/previous track buttons to enter transmission frequency mode and adjust the frequency up or down. Note: Long press the track buttons for fast FM frequency adjustment; short press for fine tuning. Please note: The product has a built-in antenna. Avoid using FM frequencies with strong local signals for optimal sound quality. Bluetooth operation may vary depending on the phone model. Some phones may not support automatic reconnection after power loss. If this occurs, reconnect manually. This product is compatible with over 95% of smartphones on the market, but compatibility with all devices cannot be guaranteed. Set call volume at an appropriate level to avoid disturbing the other party. Do not drop the product to prevent surface damage or malfunction. Package includes: 1 x Bluetooth FM transmitter