Bluetooth 4.0 Hi-Fi Stereo Speaker,Silicone Surface Portable Wireless Waterproof Outdoor/Indoor Bluetooth Speaker,NFC Supported,Built-in Battery and Microphone for HandFree Phone Call--Army Green Advanced Bluetooth 4.0 and CSR chipset delivers crystal clear heavy-duty stereo sound, ensure a fast and steady connection in door or outdoor, the outstanding connection range ups to about 30 feet open field. Also, NFC supported (Near-field communication technology). Built-in microphone and speakerphone, take hand-free phone call directly, pretty convenience especially you are doing some work which don't want be interrupted. What is more, the Bluetooth speaker could Automatically voice prompt if the Bluetooth connected. Waterproof, Dust-proof, Anti-scratch, Shockproof, High temperature Resistant and High quality Stereo Speaker. This speaker is deigned for use in wet locations but it should NOT be immersed in water. Rechargeable speaker with 3.7V 2000mAh polymer lithium battery for quick charging through built-in Micro USB port with 8 hours playback on a single full charge. Small and lightweight design with sturdy hook, very convenience to carry or hung on your backpack and bicycle, enjoy music anytime and anywhere like Travel Hiking Camping BMX or at home.