These are made to add or move the position of Coil Springs on your rig, front or rear. This particular one is made to Center the coils under the frame rails.
They are .25" thick and have the option of Coilover (2.5") springs, 4.5" springs, or 5.5" springs for the Pads & Retainers. They also come with 3/4" Grade 8 Hardware so they stay where you put them.
These are sold in pairs and easily mate up to any of our lower Coil Spring mounts & any frame.