Smart QC 3.0 Fast ChargeZeaLife Bluetooth FM Transmitter has two USB ports, which can charge two devices at the same time. One is a USB QC 3.0 port for fast charging, which is 4 times faster than standard chargers. (Compatible with : QC2.0, FCP Warwick, Samsung, HTC.) Under the maximum power, the charging efficiency reaches over 80% and can be fully charged in a short time. Bluetooth Hands-freeAdvanced Bluetooth 4.2 technology enables more stable connection and transfer faster. When connected to Bluetooth, the built-in microphone with CVC noise cancellation technology gives you clear speakers. Just press one button to answer/end/reject call/set last call. Safe driving. Multiple Music Playback ModesEnjoy lossless stereo music transmission. Allowing to play music via Bluetooth/USB flash drive (64G)/TF card (64G) connection, this Bluetooth FM transmitter will provide more stereo and duplex sound with its hi-fi system. Support MP3/WMA/WAV/FLAC/APE format files. It provides you with great car music to make your journey more interesting. Easy to Use-Insert it into the cigarette lighter socket. - Turn on the car FM radio and select the empty frequency. - Set the same frequency as the transmitter (87.5-108.0 MHz). - Connect your phone to the transmitter (named C57) via Bluetooth. Then you can enjoy music without interruption. [Multiple Protections] The Bluetooth FM transmitter is equipped with over-current protection, over-voltage protection, high voltage protection. short circuits and intelligent temperature control.