The EcoXBT by EcoXGear is a one of a kind portable audio system that combines Bluetooth audio, a lithium battery and waterproof technologies. The result is a shock resistant, floating, full range, rechargeable wireless speaker system. Stream & play your music from you Bluetooth enabled smartphone or audio device, or answer incoming calls over the built-in speaker phone. The AUX-in jack on the back of the device provides the option for a direct connection to an external audio device with a 3.5 mm connection. 10+ hours of play time at average volume level.