It has built-in Li-ion battery, directly connect with PC for re-charging. Directly connect to PC/Laptop USB Port, charge and transfer files. With a cycle switch, can be random loop. Also can use as USB Flash Drive (You can use it to store any data / files). Easy to clip-on to anything. The package contents: 1 X BLACK MINI MP3 PLAYER. 100% brand new. It comes with 3 months warranty by seller.