This is the new Arduino Uno R3 compatible. The following enhancements have been made:
1. Selectable voltage of 3.3V/5V: Arduino Uno R3 can only work for 5V. This Arduino Uno compatible USB board can select to be 3.3V or 5V.
2. When use wall adapter, it can supply up to 5V 2A compared to the original 500mA of Arduino Uno.
3. It supports 7-23V wall adapter input.
4. Both female and male headers.
5. Original Arduino Uno has ADC router issue, this board improves the layout and better ADC noise immunity.