A mechanical splice is a junction of two or more optical fibers that are aligned and held in place by a self-contained assembly (usually the size of a large carpenter's nail).[1] The fibers are not permanently joined, just precisely held together so that light can pass from one to another. This impermanence is an important advantage over fusion splicing, as splice loss, the amount of power that the splice fails to transmit, can be better measured and prevented.[2]