SIIG 4.2A USB Power Adapter 2-Port Black (AC-PW0J12-S1) Charge Galaxy Tab/Note, Surface, iPad, iPhone and other smartphones or USB powered devices 5V/4.2-amp total (shared) power output quickly and easily charges up to two tablet computers, smartphones and other USB powered devices at one time Automatically adjusts to the power requirements of device (2.1A for tablets, 1A for smartphones, 0.5A for MP3 players, etc.) Supports charging power up to 2.1A Max per port Over-Current (OCP), Over-Voltage (OVP), Short-Circuit (SCP) protections