All the hardware to mount 2 Trailer Axles to your leaf springs together in one Tandem Axle kit. The kit is designed to install 2 3/8 inch diameter Round Tube Axles, and the Hot-Dipped galvanized coating on all of the parts helps prevent rust in the harsh marine environments. This U-Bolt Kit is used to mount your trailer axles to your Boat Trailer Leaf Springs by using (4) U-Bolts and (2) 4 hole plate on each Axle. This kit includes (8) Galvanized Round U-Bolts, (4) Galvanized 4 Hole Mounting Plates, and (16) galvanized nuts and lock washers, so you can attach both springs to a single axle. This Trailer U Bolt kit is most common on boat trailers with either 2,220 lb or 3500 lb trailer axles using 1 ¾ wide springs, but it will also fit 2-inch wide springs.