3509S 3509SO.D. 3-1/2"Wall Thickness 9 GA.Wall Material SteelShaft Size 11/16" HexBall Bearing No. B3509
3530S 3530SO.D. 3-1/2"Wall Thickness 0.3Wall Material SteelShaft Size 1-1/16" HexBall Bearing No. B3530