Main Features:Stable triangle shape structure・ exquisite and attactive metal gridA2DP stereo Bluetooth transmission4W strong output power with outstanding sound qualityWater resistant・ dustproof・ anti-scratch・ shockproof・ suitable for both indoor and outdoor exerciseAux in function support all digital audio device with 3.5mm jack・ such as iPod/iPhone・ MP3・ computer・ notebook・ PSP1500mA high capacity built-in rechargeable battery・ playtime lasts for 5 hours at leastPassed the simulation environment test・ you can use it in the rain without any problem