... :(4.0mm), 4"--8" Heavy duty Industrial Caster Series AA:Heavy-duty Rubber Cast-Iron Industrial Caster(Roller Bearing)(6.0mm),4"--8" BB ... .0mm) 4"--8" Eagle-Bracket Joined Brake Caster Series AA:Eagle-Bracket Rubber Cast-Iron Industrial Caster(Roller Bearing) (6.0mm), 6",8" BB ... Bearing) (6.0mm),6",8" CC: Eagle-Bracket Rubber Cast-Iron Industrial Color Caster (Roller Bearing) (6.0mm),6",8" Heavy-duty B ...