Made of lightweight steel, the Cane Creek Valt Steel Shock Spring offers a significant weight reduction over standard steel springs. With a larger inner diameter of the spring, this spring will fit Cane Creek shocks and most other shock options on the market, but this model is designed for the 2013+ Specialized Enduro 29". Features: 1.43" internal dimension Fits Cane Creek shocks and most other options on the market thanks to larger inner diameter Made of lightweight steel Specifications: Stroke: 2.5" Rate: 550lbs Note: Cane creek and other shock brands may require conversion clip,