Sold individually. Please use the charts on the Swift Springs page to determine your needed part number and contact us to place the order. Most of Swift 10" and longer springs (Excluding the Drag racing springs and Conventional springs) are barrel design; the design is to solve all spring Deflection (bowing) problems. With bowing springs, you can expect spring rate inconsistency, and rubbing against shock body that would lead to damage on the shock adjusting perch thread. Swift designed barrel springs with ease and consistency of vehicle setup in mind, our barrel springs design have a maximum of 4" outer diameter (except B5 and B3 series)(Usually located on the center coil of the spring). Because most other manufacture do not design their barrel springs with this rule, most of their barrel springs outside diameter will differ from one rate to another. This creates a hard time for racers especially with tight clearances to test and see which rates will fit and which rate does not. A heavier rate spring can interfere with the suspension A-arm or other suspension components.