Progressive Suspension 412 Shock Absorbers (Heavy Duty) - 317mm The 412 line is the basic line of Progressive Suspension, having a low price but an excellent value for money to replace the original shock absorbers. The shock absorbers are filled with nitrogen and have a valve that allows them to be self-regulated according to the speed of the vehicle. Five preload settings. Technical features: - Color: Chrome - Compatible with: Harley Davidson Sportster XL 04-21