OPK is a leading brand in the door roller and hardware fitting industry and regards innovation as its principal goal and motivation. OPK sliding folding door solutions are perfect for residence or industrial demands. For internal and external openings, quiet, flexible, low-friction rolling systems may be used. It provides a noiseless sliding mechanism for a balanced, smooth, and soft motion for wood, glass, and aluminum doors. Users can also regulate the doors via App ios and Android or touch.