1 3/8″ High Peak Middle and Peak Side W/Keys (120 Degree) Canopy Fitting. This is the high pitch must boxed Carport kits are made with, there are only 2 fitting types. This fitting is used for the Peak Side and Peak Middle. The inside diameter of the opening is 1 3/8 inches. Uses 1 3/8 Chain Link Fence Tubing available at your local Hardware Store or Fence Company.