SMAKN DC 5V/4A 20W Switching Power Supply Adapter 100-240 Ac Compatible with most devices that use a 5V 4A or lower amperage 2.5mm x 5.5mm (Inner diameter x Outer diameter) with inside positive polarity Input: 100-240V~0.6A, 50/60Hz / Output: 5V 4000mA 20W Max