Energizer BTS-102 is a portable Bluetooth speaker with extra power for your device. The built-in microphone allows you to directly answer calls or hold conference call. BTS-102 transmits the sound up to 10M, and also works with Bluetooth connectivity, AUX, USB drive, and micro SD card. The carrying strap design makes it easy to carry wherever you go. The Energizer PowerSafe Management guarantees against short circuit, overcurrent, overcharge and over discharge for your power bank and devices.