This is the 220 volt side of the 33 KVA transformer. The 2 outside terminals are the 220 volt and the 2 middle terminals are the neutral. You can see the bottom half of the gray transformer case in the background. When the whole thing is put together and filled with oil it weights about 780 pounds, it requires 30 gallons of transformer oil. The transformer case weighs around 130 pounds, and the transformer about 320 pounds.