Rain and liquids can't harm the speaker; it can even be submerged in water. Multi-Connect: An unlimited number of speakers from this series can be connected via Bluetooth for sound expansion. Powerful Li-Ion battery for hours of playtime. Supports remote function for music control with Play/Pause/Next track/Previous track. Easily make phone calls with the built-in hands-free feature. Small and compact - fits in any bag for on-the-go convenience. Full mobility thanks to battery operation: the battery can be charged via a USB cable. LED indicator shows whether the power supply is active.