Energizer BTS-204 is a portable bluetooth speaker with extra power for your device. Built-in microphone allows you to directly answer calls or hold conference call when using the speaker. BTS-204 transmits the sound up to 10M, and also works with bluetooth connectivity, AUX, USB, and micro SD card. The carrying strap makes it easy to carry on the shoulder. The Energizer PowerSafe Management guarantees against short circuit, overcurrent, overcharge and overdischarge for your power bank and devices.