STX single-tube design Monotube shock with internal reservoir High-pressure nitrogen gas-charged 46 mm piston diameter Adjustable rebound damping Hose-mounted hydraulic preload adjuster Multiple spring rates available to accommodate a wide range of riders Top-level comfort, rideability, and performance Hard-anodized precision CNC-machined components Low-friction shaft and sealhead design Fully serviceable and repairable - Harley-Davidson Softail Street Bob FXBB (2018, 2020, 2024, 2019, 2022, 2023, 2021); Harley-Davidson Softail Slim FLSL (2018, 2021, 2020, 2019); Harley-Davidson Softail Deluxe FLDE (2019, 2020, 2018); Harley-Davidson Softail Low Rider S FXLRS (2021, 2022, 2023, 2024, 2020); Harley-Davidson Softail Low Rider FXLR (2018, 2020, 2019)