The �hlins Stumpjumper Spring sets a new benchmark for spring rate accuracy and light weight for steel springs. Fits �hlins TTX shock absorber for Stumpjumper FSR only. Made with proprietary ultra lightweight steel, it's incredible for keeping your build weight down for trail riding. Spring rates are broken down to 4 N/mm (23 lbs./in). Ultra-fine spring rates to ensure perfect set up for all weights.