The MOST ADVANCED V5.0 BLUETOOTH TECHNOLOGY - The only Bluetooth V5.0 highest technology upgrade in the market, compatible for more devices, the most stable transmission, the best resisit-interferencer performance function and most superior durability. FOUR MUSIC PLAY SOURCES -Bluetooth connected/ U disk/ TF card/ 3.5mm AUX cable, meanwhile, the bluetooth FM transmitter is compatible with most devices on the market, provides you more choices. AMAZING HI-FI STEREO SOUND - Bluetooth car transmitter, the noise and wind suppressed by (CVC) technology with resist-static design create full duplex sound quality, grants you enjoyable for lossless music in car. HIGH CLEAR CALL QUALITY - Built-in microphone feature supports hands-free talking reduce interference, the bluetooth fm transmitter for car also suitable for voice navigation for mobile phones, driving more easily. VOLTAGE DISPLAY FOR SAFETY - Car voltage display in LDesign bluetooth FM radio transmitter screen should be between 12 ~ 14.8V. (13.2V ~ 14.7V when your car engine is start, 12.2V ~ 12.8V when your car ignition is off.) Furthermore, LDesign offered you the best lifetime assurance after-sale services.