Tandem Roller Patio Door Repair Package, Stainless Track Cap 72" - Recommended for older sliding patio door threshold repair track (cap) as shown when replacing wheel / roller assemblies on old aluminum track. Package consists of Snap-On Sliding Glass Door Track Cover, 1/4" Stainless Steel Repair Cap for Worn Patio Door Rails, DIY Fix for Stuck Doors, 6 ft, (72").