3 Port Smart Phone Charger with Speaker. This unit will charge your smartphone, iPad, iPod, tablet, MP3 player and most any device that can be charged with a USB cable. You can charge up to 3 devices simultaneously. It includes a built-in speaker to listen to your device as well. Built-in to this charger is SCD (Smart Current Detection) Technology. SCD will monitor your devices battery voltage, stop charging when peak battery voltage is achieved and start charging again if battery voltage drops.