Bluetooth V4.1 with aux audio cable. Headset is soft PU coated material, with fairly large diameter of 76mm. Smart noise reduction with built-in 300mAh rechargeable battery offers 14h of continuous hearing. RB-500HB is equipped with high-quality speakers, with two independent speaker chambers designed to give users a rich, clean sound with powerful bass when wanted. Capable of connecting to two devices at one time. Also comes with headphone jack for direct input. Three colours available white, black and deep coffee.