This breadboard power supply is a companion module, which provides 5 V, 3.3 V to rails on a solderless breadboard. It is an extremely useful facility, which provides regulated voltage rails for project circuits. The module design is the form of a plug-in, which connects onto the breadboard.This module have regulated 5V USB output through for power other USB devices (your Arduinio boards), which can be extremely useful.Can switch the power 5V and 3.3V to rail of breadboard. Each rail have self switcher of 5V/3.3V/OFF.On board have general switch for power on/off. Not need disconnect power jack.We use more powerfull Voltage Regulators (LDO), for guaranteed 1A output to 5V and 800mA to 3.3V (big current for WI-FI projects)Short circuit and overheating protectionInput diode to protect circuitry from negative voltages or AC power supplies.LED power indicator.