The original type shock links connect to the trailing arm with a rubber bushing above and below the trailing arm. Compression of the soft rubber allows the trailing arm to move up and down a little without moving the shock lever. These spherical rod end links transfer all movement of the trailing arm to the shock lever so the shock can dampen even slight movements of the trailing arm. Replacement original type shock links are prone to failure at the upper end. These upgraded links are a much stronger design that should hold up better than replacement original style links.