The ProRate Spring is designed to fit both DVO Jade and Jade X rear shock models, offering the longest spring life of any lightweight steel spring on the market. FEATURES: Up to 125lbs of progressive rate coil; great for big-hit support, aggressive riders or linear linkage designs Lightweight and high-quality Japanese steel Retains spring-rate up to 1,000,000 compressions SPECS: Material: Steel Spring Weight: 475lb Stroke: 65mm