MORryde 213.3008 UO12-021 Heavy Duty Shackle Upgrade Kit, Stock/Equaflex 3-1/8" Shackles - Tandem Axle Thicker shackles for added strength Bronze bushings for more durability Greasable bolts for less maintenance Fits Stock or Equaflex with 3-1/8" shackles Tandem Axle