the following example is for you reference.
Hardware galvanized door and window roller: H1-5

      Longyou Open Electromechanical Technology Co. Ltd, in sliding parts of a leading Chinese manufacturers, was founded in 2002, mainly the production of pulley, pulley, load sliding door system, industrial sliding door hardware, track, dustpan, nylon wheel, other windows accessories, exported to Europe and the United States, Dubai and the Middle East.