nylon wheel medium duty rigid castor 1)size:50,60,75,100mm 2)loading ... capacity:40,50,50,60kg nylon wheel medium duty rigid castor1)housing:made of pressed steel, zinc plated, double ... ball bearing swivel head, medium duty version.2)wheel: of high quality polyamide, with ... , impact proof and corrosive resistance. nylon wheel medium duty rigid castor