Features: 1) Adopted with 3D sound coding technology, which maintains the Hi-Fi effects of MP3, MD, CD and TV 2) Built-in wireless FM stereo transmission 3) Draws power from cigarette lighter jack in the car (car 12V DC power) 4) Color: black 5) Dimensions: 20.5 x 10.5 x 4cm Specifications: 1) Voltage: 12V DC 2) Operating current: 3) FM frequency: 4 FM channels (107.5, 107.1, 106.9, 106.7MHz) 4) Channel separation: ≥72dB 5) Audio source: USB flash disk or MP3 player 6) Transmitting distance: up to 30 meters Instructions: 1) Plug the unit into cigarette lighter of your car directly 2) Plug USB flash disk into car MP3 transmitter 3) Select one from 4 FM channels that do not interfere with local broadcasting stations 4) Tune the frequency of your car\'\'s stereo to the same as the unit 5) Press the play button on the FM modulator to enjoy your music Inner packing: 1pc/plastic box N.W.: 42g G.W.: 60g Outer packing: 100pcs/ctn Carton dimensions: 55.5 x 36.5 x 26cm G.W.: 6.84kg (gift box)