Heavy Duty Fitting(S) (Galvanized Steel) W/ Tightening Eyebolts, 1Pc, Welded Connections Our 1 3/8 Fittings Have An Inner Diameter Of 1 3/8 . Which Works With 1 3/8 Emt Pipe Or Chain Link Fence Top Rail That Has An Outer Diameter Of 1 5/16 . You Can Get This Pipe At Most Hardware Or Fencing Stores Great For: Top And Bottom Of Set Ups, Flat Top Canopy Set Ups, Flea Market Booths, Craft Fairs, Batting Cages, Golf Simulator Cages, Garden Trellis, Clothing Racks, Banners, Sukkah Kits, Green Houses