Linear rate, dual rate, triple rate, what do you really need? We actually use all 3 variants depending on the vehicle, height and capacity requirements. Linear coils have a single spring rate and are evenly spaced top to bottom which makes for a great spring for most applications. The main advantage being that the coils don€™t touch each other, which can lead to wear and tear and coil failure. The dual rate coil has a tight set of coils usually at the top, and then a second set of coils with more traditional spacing below. Dual rate coils do not ride any better than single rate coils despite popular belief. The first rate is usually completely compressed and acts as a spacer, its purpose is to provide a longer free length coil so at maximum articulation the coil doesn€™t unseat. In most applications, including the front of our JL/JT 2.5€ť and 3.5€ť lift kits the coils do not unseat and there is a top post and bottom bump stop present so coils cannot fall out even at max articulation. But in the rear, there is no coil post or lower internal retainer, and therefore a dual rate coil is necessary, or in the JT€™s case a triple rate coil due to the additional cargo area and weight. All of our coils are powder coated black using a new SealKor finish which is a zinc rich powder coat  to help in the prevention of rust and corrosion. Specs: Made in the USAExtremely durable materialsProvide perfect balance between on and off roadOffroad flex and weight carrying abilityAbsolutely the best, most durable coil springs available on the market Set consists of: Rear coil springs +2,5″ (pair)