FecPecu Bluetooth MP3 Player, 4GB, Blue 50 hours playback's battery life, and only need to charge for 3-4 hours. You can charge it in computer or the general charger which output is "5V, 0.5-1" The memory card slot can support 64GB, so can store more music or other files Needn't to insert the headphone or speaker, you can enjoy favorite music and listen to FM radio with the Bluetooth mp3 player. Bluetooth support version over 3.0 and below 4.1, not support V4.1 Shuffle favorite songs in any folder or playlist which you selected, enjoy shuffle fun Clear lossless stereo sound, support audio formats: MP3, WMA, OGG, WAV, APE, FLAC, and ACELP (Not support Audible and WMA DRM directly)