The E270 is a portable player with a built-in MP3 player. You can play your music or your pre-recorded announcements in MP3 or WAV file format, stored on a TF card (Micro SD) or streamed via Bluetooth from an external device. The Class D digital technology ensures loud and clear sound output with very low power consumption. Its lithium battery can guarantee up to 10 hours of continuous playback. And when the battery is low, simply plug the adapter into the outlet to recharge it. This portable amplifier is easy to carry and is suitable for teachers, tour guides, speakers for small groups, or as a speaker for your smartphone or for audio streaming on the table.