This is a high quality switching ‘wall wart’ AC to DC 5V 2000mA USB Micro-B wall power supply manufactured specifically for SparkFun Electronics. These are switch mode power supplies which mean the output is regulated to 5V and the capable output current is much higher (2000mA).
These wall adapters are perfect for supplying power to many single-board computers like the pcDuino or the Raspberry Pi. Please note, this specific supply (5V/2A) is also FCC/CE certified and works with 100-240VAC inputs.
Note: These power supplies have US style plugs. They will work with 240VAC but will require a country plug adapter.