This kit comes with complete instructions new center pins and new leaf alignment clamps. Order one kit per axle. Add-A-Leaf kits are sold as pairs except for dual add-a-leaf kits which are sold in sets of four. U-bolts are NOT included in add-a-leaf purchasesAdditional Attributes:GTIN:00658848618675Installation Time:2 HrsProp 65 (C| R or CR):CRProp 65 Short Label:WARNING: Cancer and Reproductive Harm https://www.p65warnings.ca.govProp 65 Warning Label:p65.jpgProp 65 Yes/No:YesPvg Product Status:ActiveExtended Information:Emissions :Emissions Compliance ExemptLife Cycle Status:Available To OrderPackaging:Quantity of Each:1Package UOM:EADimension:54.5000 x 5.5000 x 4.0000 inchesWeight:36.7000 PG