PROGRESSIVE SUSPENSIONPart Number : PR-31-2542 PR-31-2542 Progressive Suspension Adjustable Monotube Fork Cartridge Kit -1 Inch Lowered For 2018-2021 Softail FLDE, FLFB/S, FLHC/S, FLSL, FXBB, FXBR/S, FXLR ModelsFor 49mm conventional forks. Adjustable pre-load. Asymmetrical monotube suspension design is used in the latest top-end sport bikes and motocross applications.True High Performance and the best Progressive Suspension has to offer. Since the best damper is a large damper, this damper is so large it leaves no room for a spring.The aluminium sealed deflective disc cartridge damper system is nitrogen filled to reduce oil foaming. The oversize spring system is installed in the other fork tube and comes with externally adjustable pre-load.Kit provides great road holding, gives no fork flex issues and is available in stock and lowered heights. It will lift your bike to new unmatched ride levels, outperforming any suspension upgrade on the market today. FITMENT INFORMATIONSoftail Deluxe - FLDE: 2018-2020Softail Fat Boy 114 - FLFBS: 2018-2024Softail Fat Boy - FLFB: 2018-2020Softail Heritage Classic 114 - FLHCS: 2018-2021Softail Heritage Classic - FLHC: 2018-2021Softail Slim - FLSL: 2018-2021Softail Street Bob - FXBB: 2018-2021Softail Street Bob 114 - FXBBS: 2021-2024Softail Breakout - FXBR: 2018-2020Softail Breakout 114 - FXBRS: 2018-2021Softail Low Rider - FXLR: 2018-2020.