The module can provide 5V power for two sets of independent electronic building blocks module so that the two modules can be more easily connected together. For example the switch module output switching value (high or low level) and it can control the ON and OFF of the LED module. So the switch module connects to the mini-USB power input interface modules and the LED module connects to the corresponding output port and then connect the USB power supply the switch module is very easy to control the LED. Module features are as follows: 1. Can connect two sets of modules 2. USB interface for 4.5 ~ 5.5VDC power supply 3. Should be less than 500mA supply current 4. Standard 3-wire electronic building blocks interface easy to use 5. Four M2 screw mounting holes for easy installation