CS R Bluetooth 4.0, power saving,faster and more stably transfer, transmission distance10M ( withnot obstructions between them) , paired with convenience ( no need to enter a passcode) , better compatibility with bluetooth devises The design of stereo power and 4W double-coil loudspeaker can make the tune quality much truer and steadier. Built-in 3.7V/1000mAh rechargeable lithium battery can provide power for about 8-hour playing (being different based on volume and music) Protection level of the product reaches IP64. which can effectively prevent liquid/dust entering into the machine and prevent the damage caused by the falling. BQB \ CE \ FCC \ ROHS certification, quality assured. Easy to carry, well-suited for both indoor enjoyment and outdoor carrying.