... , use high efficient components, it can work more than 15h.3.Play type: MP3,WMA,WVA format, maximum capacity 32GB TF ... . Red light flash, needs to recharge, after flash 1 min,headset shut off auto. Charging, red light keeps flashing, light stop ... freely,when walking,shopping,running,doing housework,fixing things Popular wireless headset with TF card player