This pair of black nylon anti-jump blocks is used to prevent your door from easily being lifted up and off your flat track. They fill a 3/8″ space between the top of the door and bottom of the flat track. They mount on the top edge of your door behind the hanger strap.
If you need to fill a bigger gap between the door top and track, see the Anti-Jump Plates listed in this category.
Save 15% off Flat Track and Select Modern Hardware, use code: spring2018