RS55601 Features:

• Progressive Engagement Valving-helps to reduce harsh impacts by controlling the flow of fluid early in the shock's travel range
• Larger fluid capacity due to the enlarged 2.250 in. twin tube body, helps keep shocks cooler
• Minimized air-to-oil mixture by pressurization of the shock up to 150 PSI
• 16 mm Nitro-carburized rod for additional strength and corrosion protection
• Polyurethane rebound bumper limits wear and tear at the peak point of travel
• Reduced road noise thanks to black natural bushings
• Low friction/ self-lubricating seal keep the road and trail debris out of your shocks 
• A fluon (glass & plastic material) banded piston provides an incredibly slippery surface to allow quick and smooth travel within the cylinder
• High-stress mounting points are strengthened by double welding the mounting loops