This is a basic single add-a-leaf. These offer 1.5" of lift and smooth the transition from ride height to compressed height. Made from domestic spring steel with teflon wear pads, these springs will help prevent the harsh bottoing the stock Frontier leaf springs exibit. There is no los or gain of load capcity, just a small lift and better ride quality. These can be used with stock u-bolts to replace the overload spring or can be used in conjunction with the overload (new ubolts will be required). Kit includes 2 springs and new center pins.