[. . . ] Thank you for purchasing this product, please read the manual carefully before operating, and reserve it for future reference. 4V, negative ground Maximum power output: 4X25W or 2X20w Suitable speaker impedance: 4-8ohm Weight: Dimensions (WxHxD): 1. [. . . ] Note: 1 According to models with different wiring harness to connect the definition of the specific content, please refer to the model label. 2 Specifications and the design are subject to change without notice due to improvements in technology. - Radio mode - Auto search the station from high to low EN-2 - Radio mode Auto search the station from low to high - MP3 mode Select the next track 10. MP3 track fast search Press the button to select MP3 folder back/ ahead Radio tune by step Hold it more than 2 second , switch to the manual mode, press the button step search the station from high to low or from low to high. The unit will play the music automatically and the LCD will show CARD. Push SRC button and switch to non CARD mode, slightly press SD card, take out the card when it was pop out Radio mode:press DISP button, Turn and turn display PTY/Clock/current channel frequency MP3 playback mode:press DISP button, Turn and turn about folder name/file name/ID3 TAG/ Clock Then press DISP more than 2 seconds, minute display blinks, rotate the VOL knob to set minute, press DISP button again, hour display blinks, rotate the VOL knob to set hour , press DISP to confirm. Insert USB into the connector and the unit play the music in the USB storer automatically, and the LCD will show USB. Push the SRC button and switch to non USB mode, then take off the USB storer. Radio seek automatically Auto serach the station from high to low or from low to high. SD card support USB flash memory 2 in 1 (SD) support Fat 12/fat 16/fat 32 is possible USB 1. [. . . ] Due to different formats, some models of storage devices or MP3 players may not be read. Unable to insert USB The memory card or USB device has been device or SD/MMC inserted the wrong way round. [. . . ]