Fox Suspension Steel 2.35" Travel Rear Shock SpringThis mountain bike (MTB) rear shock spring features a hard-wearing steel construction, which offers excellent durability as you conquer every trail-riding adventure. All standard steel springs are black and are marked with their spring rate in lbs/in (in 50lb increments) and the total travel of the spring itself. Standard black springs should only be paired with shocks having less travel than the travel marked on the spring itself. Features: Material: Steel Use: MTB Type: Rear Shock Spring Spring Travel: 2.35" Inner Diameter: 1.385 inches (35mm) Compatibility: All Fox coil rear shocks Size: Multiple options available to selectManufacturer’s Part Numbers: 039-03-016 Black 500lb 039-03-017 Black 550lb 039-03-018 Black 600lbBuy Fox Suspension Components from Chain Reaction Cycles, the World’s Largest Online Bike Store.