ON THIS WIKI
The MFE (short for Multi-Functional Energy Transmitter) is the second tier of energy storage devices in IndustrialCraft 2. One MFE is capable of storing up to 600,000 EU making it the equivalent of 15 BatBoxes. The MFE can accept a maximum power of 128 EU/p from any of its 5 input faces and emits a current of 128 EU/t from its output face (the face with the dot).
Since Minecraft 1.6 and IndustrialCraft2 Experimental an intermediate tier of energy storage, the CESU, has been introduced, which has the same properties as the old MFE. The new MFE itself now has the capabilities of an old MFSU, making it the third tier of energy storage with a maximum voltage of 512 EU/p and a storage of 10 million EU.
The MFE can also accept a redstone input. This will change the action of the MFE depending on which setting is selected. This setting can be changed by clicking the button with an image of redstone on the top right. A lever can be attached to an MFE by "sneaking" and right clicking on it.