Made of high-quality materials, durable and corrosion resistant, perfect for Boat Trailers Suspension kit includes equalizers and hardware for attaching 4 leaf springs to the hangers on your trailer's frame. Features: Suspension kit lets you attach 4 leaf springs (sold separately) to your trailer frame. Works with 1-3/4" wide double-eye springs Hangers sold separately. Equalizers transfer load and impacts from one axle to another by permitting movement between the axles. Springs attach to ends of equalizers with included hardware. Bolts secure equalizers and springs to the hangers on your trailer Shackle link assemblies with bolts secure springs to equalizers Kit includes: 2 Galvanized Equalizers 7 3/4" 8 Galvanized Shackle straps 4" (2-1/2" from center hole to center hole.) 14 Stainless Steel Bolts with locknuts 8 Stainless Steel Squared U-Bolts 1/2"x 2 1/8"x 7 3/8" 16 Stainless Steel Nylon Insert Lock Nuts 4 Galvanized axle plate 4" Specs: Application: tandem-axle trailer with 1-3/4" wide double-eye springs Equalizer dimensions: Distance between outer shackle bolt holes (center on center): 7-3/4" Height of side bolt hole to hanger bolt hole: 2-7/8"" Shackle strap length: 2-1/2" from center hole to center hole. Bolt dimensions: 3 1/2 " long x 1/2" diameter U Bolt dimensions:1/2"x 2 1/8"x 7 3/8"