Water-proof and sand-proof design - Safeguards the subwoofer sound speakers against water submersion, plus dust and other small particles, so you can listen to music both indoors and outdoors.Inspired by jeep that designed to be waterproof, shatter-resistant and dust-proof, what makes it fashionable and durable. ? Crystal Clear Sound - Enjoy an impressively sound quality and robust bass realized through a 3W audio driver. The sound is nice and crisp. ? Built-in microphone - hands-free voice chatting, set your hands free to enjoy free and easy life. ? Built-in 1500mAh high capacity battery - Provides extended playback, enables you to stream music for up to 5-8 hours on a full charge. ? Bluetooth 4.1 Technology - wirelessly connect from up to 32 ft away with your iPhone, iPad, Android / Windows smart phones, tablets, and Bluetooth enabled music devices.