Snow tire chains are devices that are placed over the tires of a vehicle to improve traction on snowy or icy roads. They are typically made of metal, and they work by digging into the snow or ice and providing a gripping surface for the tires.
Snow tire chains can be an important safety feature, especially in areas where snow and ice are common. They can help to prevent accidents by providing better traction and control on slippery roads. In some cases, snow tire chains may even be required by law in certain areas.