Valmont Model 4B180 aluminum quad-top-mount, 180-degree bullhorn bracket.; Tenon loading is calculated for weights based on a 100 M.P.H. constant wind with a 1.3 gust factor located 30' above grade. When loading requirements exceed these limits contact your Valmont representative or Valmont Industries, Inc.; 2-3/8" O.D. tenons and mounting arms - other sizes available upon request.; Bracket hubs slip-fit 3", 4", 4-1/2" and 6" O.D. pole tops or tenons.