251S 251SO.D. 2-1/2'Wall Thickness 11 GA.Wall Material SteelShaft Size 11/16" HexBall Bearing No. B251
297S 297SO.D. 2-9/16"Wall Thickness 7 GA.Wall Material SteelShaft Size 11/16" HexBall Bearing No. B297
3509S 3509SO.D. 3-1/2"Wall Thickness 9 GA.Wall Material SteelShaft Size 11/16" HexBall Bearing No. B3509