DVO ProRate Rear Shock Spring - 350/400 x 55mm Black. The ProRate Spring is designed to fit both Jade and Jade X rear shock models offering the longest spring life of any lightweight steel spring on the market.

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 1000000 compressions