Single axle kits include axle tie plate kits, 1-3/4" x 25-1/4" double eye leaf springs, front and rear spring hangers, shackle links and all necessary hardware to install axle. Tandem axle kit includes additional parts for the second axle along with cast spring equalizers. Welding of spring hangers to trailer frame will be required. Axle Tandem Hub 5-Stud Size 2-3/8" round w/ 1-3/8" x 1-1/16" spindle Capacity 3500 lbs.