About AEAGLE Leaf Springs:--Sturdy Steel: We choose high-quality 60Si2Mn (A Steel with Higher Hardness) to make our products strong and durable. --Good Corrosion Resistance: Our Trailer leaf spring kit with anti-rust coating.-- Well-selected and Tested: To ensure that Leaf springs can withstand the load impact of the wheel on the frame, reduce the severe vibration of the body, and maintain the stability of the vehicle and its adaptability to different road conditions.--Stable Elastic Characteristics: It can improve the smoothness and stability of Trailer driving, thus improving comfort.--Ideal Solution: Seamlessly replaces leaf springs damaged by overloading, collision, cracking, or corrosion, or are due for replacement when the vehicle sags, bounces excessively or rides unevenly.Product Parameters:--1750 lb Capacity Per Spring for 3,500 lbs Trailers--Eye to Eye Length: 25-1/4 inch--Free Open: 3 inch-- Width of Leaf: 1-3/4 inch--4 Leaves--9/16 inch Bushing Dia, 2 Bushings Installed for Each Spring--Leaf Thickness: 5/16 inch Kit Includes:--2 x 4-Leaves Double Eyes SpringsReplaces for Part Number:--Replaces for SW4B