USB To RS232 TTL PL2303HX Auto Converter Module Converter Adapter For Arduino Pins are clearly labeled and 500mA self recovery fuse for protection Two data transmission indicators can monitor data transfer status in real time Reserve 3.3V and 5V pin interface,easy for different voltage system that need power The entire board is coated by high quality transparent heat-shrinkable sleeve, making the PCB contained in insulation 1 x USB To RS232 TTL PL2303HX Auto Converter Module