A professional dual 15 '' speaker with BT receiver, MP3 player, powerful mid-low woofer and a high dynamic compression horn for excellent sound. Unlimited flexibility in placement as a result of the BT technology. The MP3 player plays audio files via USB stick or SD card. The slave output can external speakers easily through loops. The durable shock-resistant molded lightweight enclosure features a sturdy metal grille that protects the woofer. This dual active speaker can be used stand alone and is ideal for use in bars, restaurants, small theaters and halls, gym, conference rooms and on stages.