Usage Tips:Crystal Clear Music Streaming - T25 is anti- statics designed, and equipped with noise and wind suppressed by CVC technology that can achieve full duplex sound quality. You can stream music on your car stereo via Bluetooth/ USB Flash Drive (32GB) / microSD Card (32GB). WMA MP3 WAV APE FLAC music formats are all supported.Intelligent Dual USB Ports & Safe Charging - Coming with 2 USB ports(5V-2.4A and 5V-1A), you can charge two devices simultaneously. Built-in over-current protection, over-voltage protection, intelligent temperature control, short circuit protection, it will effectively ensure safe charging.Hands-Free Calling & Voice Navigation - Bluetooth provides a stable connection, while Noise Suppression (CVC) technology and echo-cancellation grants an amazing hands-free calling experience. Besides, you can also get clear voice navigation from your phones app, which means driving will be more safely.Car Battery Voltage Detection & Blue Ambient Light - The FM transmitter will display cars voltage when plugged into the cigarette lighter. Keep abreast of car battery health at all times to avoid problems when driving. With the circle of blue backlight around this car charger, it will greatly simplify your operation for safer driving. (Please compare the size between the transmitter and your car cigarette lighter )Wider Range & Compatibility - This Bluetooth transmitter is well compatible with most of the smartphones and more devices that equipped with bluetooth function. It will automatically connect to its memorized paired Bluetooth device when power on. Also, with the wider range from 88.1MHz - 107.9 MHz, you can get more stable and consequent music experience without interference