Features: Stylish, lightweight and has great sound quality. Supports TF card play mode and FM Radio. Built-in high-performance 3.7V 150mAH rechargeable lithium battery offers high safety and stability, and it has over-charge and over-discharge protection. The rechargeable lithium battery can offer you about 8 hours of music playing time. Special structure design for comfortable wearing. Applications: Extremely suitable for bicyclist, runners, joggers, walkers, climbers, etc. Easy to use: Switch the power button to on and the LED indicator lamp lights, and then press the function button (MODE), and the default status radio is enabled, the earphone works. MP3 player function: After inserted TF card into the card slot of the headphone, the headpone will automatically switch to MP3 play mode to play music. Press forward or rewind to perform the corresponding operations. Press button || to pause play mode. Volume control: Long press the Forward / Rewind button to volume up or down Power off: Push the switch to OFF