When installing a suspension system, it is crucial to replace U-bolts that have been stretched during the tightening process. Although re-used U-bolts may appear tight, they have actually lost their strength and can cause damage to the spring bolts and suspension components. Tough Dog U-bolts are made from high tensile steel and have the correct thread length for larger, heavy duty leaf spring packs. Specifications include 1 required per coil and compatibility with various Nissan Patrol models.