2 in 1 Function: You can flip in for normal headphone use, fip out for music speaker use NFC function helps you fast pair with headphone which is convenient and time saving . Multi-mode:Many modes for you to enjoy music like Bluetooth mode, FM Radio(please connect the headphone with your cell phone by the audio cable when in FM mode), TF card and Audio in.Hand-free to make a call or answer a call with built in mic while running, biking, and other forms of exercise.It's noise cancellation feature provides you with amazing sound quality especially when you are outdoors surrounded with noise! Perfect Design :Adjustable headband for different head size, Foldable design and light weight make it more portable to carry, Skin-friendly protein cotton earmuffs for long time wearing which refuse to oppression