27 inch Double Eye 4 Leaf Spring that is rated to 1750 lbs per spring. This would bring a pair of these 27 inch Double Eye Trailer Springs to 3500 pounds and are suitable for trailer axles rated the same. Spring Measurements and Specs:Eye to Eye Measurement 27 inches (Free Length Measurement)-Does your spring measure slightly more than 27 inches, lets say 27 3/4 or so? You may have your trailer loaded, or the spring may be old and flattened out. It is not uncommon for leaf springs to measure longer than what the stock size is listed. Free Arch Measurement (see picture) 3 inches-The free arch measurement is based off a stock, brand new spring. Your leaf spring will more than likely be flattened out, or possibly broken. This Trailer Leaf Spring measures 1 3/4 inches wide9/16 inch bushings come installed in the spring, 1/2 inch are available as an add on.These springs can be used on both square tube or round tube trailer axles on boats or land trailers. The only difference is in the style of U-Bolt Required to mount the spring to the axle. Check the condition of your U-Bolts and the required size and check our U Bolt Kits out here. Leaf Spring U-Bolt Kits. Available in raw steel, hot-dipped galvanized, and stainless steel. If you are planning on replacing the hangers, (brackets that are either welded or bolted to frame that hold leaf spring) and shackles (2 shackles towards rear of spring assembly for single per side or 4 in the middle for tandem trailer per side) We have single and double spring hanger kits available for Weld On assemblies that include all the necessary replacement hardware. Weld on assemblies are more common on non marine trailers.Spring HangersBoat trailers will commonly have bolt-on hangers or spring sliders.