These headphones ARE NOT portable and are demo models which means that the cable is not detachable and must be connected to a power supply to work.  They do not have or can accommodate batteries.  And they do not have a power supply cable/adapter (AC adapter Model: SY-0630).  These Beats are in very good condition and show little wear and sound incredible!!  This listing includes the headphones you see in the photos and nothing else.  You will need to purchase the power supply separately or they will not function.