Bought size 245, recommended size for my tire (225/65R17). After tightening to the last tendon, they only remained thrown over the tire and were no longer tightened. After contacting Konig and showing them these pictures, they recommended trying the smaller size 240. Thank goodness I bought these through Revain with their amazing return policy. Many retailers will not accept returns of tire chains, and if they do, there is usually a restocking fee for what appears to be used. The difficulty lies in fitting them to the tires without fouling/damaging them because you have to ride them to fit them properly.