Portable 3.5mm wireless audio transmitterTransmit FM signalsBuilt in lithium battery that can be rechargedUltra-low work voltage designYou can insert into your own audio device(MP4/MP3/Mobile phone)， the music signal will be transferred to car audio to playProvides handsfree conversations through your car speakerHelp you to realize talking， charging and playing music on the go!3.5mm stereo headphone plugOutput: 5±0.1VCurrent: ≤600mAStorage Temperature: -20℃~+50℃Working Temperature: -10℃~+40℃Battery Capacity: 120mAhFM Frequency Band: 87.5-108.0MHZTransmitting Range: About 15mColor: Black， WhitePackage Included:1 x Car Audio Transmitter