caster Fork: Zine plated, Hollow screw stem Wheel:cast iron, solid rubber, black Loading capacity:180-300kgs Dia.: 5',6', ... hollow screw stem,zinc-platedWheel: wheel center made of cast iron, tread:solid rubber, black,with grase hole.Loading capacity:180 ... . Optional wheels: PU wheel (PP core), PU mold on cast iron wheelModel: 1176