CURT certified s-hooks offer a quick, easy and safe way to connect chains from the towing vehicle to the trailer. These hooks are heat-treated and zinc plated for a durable finish. They are available in GTW capacities of 2,000 to 7,600 lbs. with diameters of 3/8â€, 13/32â€, 7/16â€, or 17/32â€. Hooks must meet or exceed the maximum GTW of your trailer, so keep that in mind when purchasing.