Clear sound quality With built-in microphone, it supports hands-free calling to enable you to drive more safely and easily. The high-performance microphone with echo cancellation and noise suppression technology provides you crystal-clear sound quality for calls and music. Universal compatibility: Fast-Charging Dual USB FM transmitters are available for most Bluetooth-enabled devices such as iPhone, Samsung, HTC, LG, Blackberry, Tablet, iPad, Camera and Navigation devices. Voltage detection & intelligent navigation: Test the battery voltage of your car before driving, and the built-in microphone voice broadcasts real-time road conditions to ensure traffic safety. Large LCD Display Screen: 1.7in LCD display screen clearly shows your car voltage when plugged in, phone number for incoming call and song name when stream music from U disk or TF card. Folder memory playback: You can select your favorite folder for playback, power off memory function, and continue to replay after power on.