Designed for use with manually operated curtains. Hanger wheels are made of Delrin and are equiped with Delrin bearings to insure a smoothly operating curtain. Hanger frame is made of steel, bumpers prevewnt the hanger wheels from running together. Hangers will operate in a curved section of track when it is necessary to run the curtain around corners. Hangers should br placed 12″ to 14″ apart, depending on the weight of the curtain. Capacity: 25 lbs. to 75 lbs. maximum. Typical Applications: stage curtains, machinery enclosures curtain, sound reducing curtains, etc.