Safety chains are metal links used to secure trailers to towing vehicles, providing an extra layer of safety. They are typically attached to the hitch of the towing vehicle and the trailer's frame. In case the primary hitch fails, safety chains help prevent the trailer from completely detaching, reducing the risk of accidents. These chains are usually made of strong steel and come in various sizes and weight ratings to match different trailers. Proper installation and maintenance of safety chains are essential for safe towing, ensuring they are not too loose or too tight, which can affect their effectiveness.