[. . . ] 4 buttons credit card-MP3 Instruction Manual Appearance and buttons Battery: The unit is power by 3. 7v built-in lithium-ion battery, when power becomes low, LED will shine slowly, please charge in time. [. . . ] Press " /VOL-" shortly skip to previous song; press " /VOL+" to skip to next song. Volume adjustment: Press and hold /VOL- to decrease volume; press and hold /VOL+ to increase volume Button R: press R to restore. Low power, LED shines slowly When charging via USB, LED shines, when full charge, LED lights constantly. Using USB disk The player is a standard USB Disk, supports systems over Windows2000 (it's unnecessary to install the driver), Mac OS X 10. 3 and above, Linux 2. 4. 2 and above. How to connect with PC Power on the player, connect the unit to the computer via the supplied USB cable. The player enters U-disk mode automatically. 2 Trouble Shooting No power supply No voice in the earphone Make sure the player had been powered on. [. . . ] Check if there is enough memory Cannot download music files normally List of accessoiries: 1x Earphone 1x USB cable 1x 2, 5 mm to 3, 5 mm plug (for earphone connector) 1x Instruction manual 3 [. . . ]