Breadboard Power Supply (3.3V-5V)Use this power regulation module to provide a 5v and 3.3v power supply to your breadboard-based project. This power supply board is designed to plug into a breadboard panel with 2 power distribution strips. The module can be powered by a USB port or an external power supply 7-12v. The module has two independent power lines, which can be set to the output voltage of 5v or 3.3v, or completely remove power from the line. The module has an on / off switch to turn on and off module. It comes with reverse polarity and short circuit protection, which greatly helps during building and testing circuits on the breadboard. Specifications and features:- designed to fit the standard mb102 breadboard power supply comes with on/off switch green led power indication built-in protection against short-circuiting.