U-Bolt Mounting Kit For 3,500 lb Trailer Axles with 2-3/8 Inch Round Tube Diameter Kit Includes - (4) U-Bolts, (2) Tie Plates and (8) Nylon Lock Nuts U-Bolt Measurements - 5 Inch Length, 2.94 Inch Width, 1/2-20 Thread Tie Plate Measurements - 5.92 Inch Length, 3.75 Inch Width, 2.94 Inch Hole Centers Nylon Lock Nut Measurement - 1/2"-20 Thread / Pair of weld-on spring seats are included. Economically priced kit - Perfect for those on the road repairs.