The board includes 500mA fuse protection, EMI filtering, power LED indicator, RX and TX LED indicators, and a voltage level shifter that makes it compatible with 3.3V and 5V boards. This way you don't need to check the jumper if it outputs 5 or 3.3V so you don't risk burning your microcontroller. It works with both voltages.
Eagle schematic and board layout are available for download down below.
