At the corners of cables such as optical cables, a kind of power fittings - strain clamps are often seen. The tension clamp is used to fix the wire to bear the tension of the wire, and hang the wire to the metal fitting on the tension string or tower. It is used to fix the wire or lightning conductor on the tension insulator string of the non-linear pole tower, and it acts as an anchor. Spiral aluminum-clad steel wire has extremely strong tensile strength, no concentrated stress, and plays a role in protection and auxiliary vibration reduction for optical cables.