Drop the insert into your rockered rail or full rocker shoe. Fit it tight so you can lay the shoe and insert on the foot. Adjust the pitch of the insert to meet the intended purpose. Weld the insert in place using COR-AL flux coated aluminum rods listed below. Welding this frog support insert in the rockered rail shoe helps prevent sagging of the frog on the long toe loe heel "slam dunk" foot. We offer different shapes within the same size range to better fit your specific application.