I have been using these swivels for over 10 years with fantastic results. I light line ocean fish and use the #7 for 10-12 LB. test and # 5 for 15-20 lb. I have landed fish up to 40lb on the #7 so yes they are durable.
Due to poor scale representation and lack of comparative size chart, I received swivels too large for the application I wanted. (Freshwater). I will however use them for light saltwater even if I didn't need them. Cabelas, please list all tackle length in inches and forget the less precise use of sizes like O, 1/0 etc.