3-link or 4-link tower for the axle tube. Choose from  7, 8, or 9 inches of vertical separation from axle centerline. Axle sizes available are 2.5", 2.75", 3.0", 3.125", 3.25", and 3.5". Bolt hole diameter 9/16" and made from .250" plate. Includes 1 tower. Part #s 1004 (7in), 1005 (8in), 1006 (9in).