This set of four marine coated 20 inch Double Eye 3 Leaf Springs is rated to 1850 lbs per spring, bringing a pair of these 20 inch Double Eye Trailer Springs to 3700 pounds, so these are commonly used on 3500 lb trailer axles. The marine coated finish provides extra protection against corrosion and the elements, so these springs are perfect for use on boat trailers or utility trailers traversing areas with a lot of salt or rain.