Foam Rail crossbars were designed to work with all ZipWall spring loaded poles and are sold 2 per pack. The included T-Clip is used to mount the poles at the center of the Foam Rail. The Foam Rail crossbars were not designed to hold up the plastic sheeting. They push the plastic or barrier material against the ceiling after the barrier has been built using ZipWall poles placed 8 to 10 feet apart.