KIWI Double-U Insulators are used on end and corner posts. The electrified wires go on the inside of the corner posts. It is used like a porcelain donut where a loop of non-electrified wire holds the insulator to the post. However, they are much stronger than the porcelain donut. They work best when crimping sleeves are installed in the wire loop to bring the wire together near the insulators. The I46 has metal embedded in the plastic to keep the wire from cutting through.