Standard U-Bolt, Standard U-Bolt, Aluminum, Finish Plain, Thread Size 1/2 In.-13, Thread Length 1 5/8 in, Inside Length 4 1/2 in, Inside Width 3 in, Pipe Size (In.) 2 1/2 in, Characteristics Has Coarse Rolled Threads, for Steel or Wrought Iron Pipe Sizes, Includes 2 Nuts