Features* Stable triangle shape structure， exquisite and attactive metal grid* A2DP stereo Bluetooth transmission* 4W strong output power with outstanding sound quality* Waterproof， Dustproof， Anti-scratch， Shockproof， suitable for both indoor and outdoor exercise* Aux in function support all digital audio device with 3.5mm jack， such as iPod/iPhone， MP3， Computer， Notebook， PSP...* 1500mA high capacity built-in rechargeable battery， playtime lasts for 5 hours at least* Passed the simulation environment test， you can use it in the rain without any problem SpeacificationRated power: 2W x 2Speaker unit: 1.5" x 2Frequency response: 80Hz-20KHzPower supply: built-in Li-on rechargeable battery or mini USBUnit size: 150*56*56mm Accessories: Bluetooth Speaker*1， USB Cable*1， Audio Cable*1， User Manual*1， Layard*1