The Öhlins Stumpjumper Spring sets a new benchmark for spring rate accuracy and light weight for steel springs. FEATURES: Ultra-fine spring rates to ensure perfect set up for all weights. Spring rates are broken down to 4 N/mm (23 lbs./in). Fits Öhlins 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.