4-16FT Sliding Barn Door Hardware Kit Single Double Doors. Material: Track– Carbon Steel, Black Roller–High quality steel wheel material–Premium nylon Door Max Weight Capacity: Up to 330lbs every pair rollers Fits sliding Door Thickness: From 1 3/16″ to 2″ The top of the Doors to the ceiling : Min distance is 6. For Single Door, Package Includes. Spliced rail with pre-drilled holes. Wall hangers+ Track Screws + Wood plugs (according the track holes quantities). Only sliding door hardware kit. Don’t include the Door. How to Choose Track Size. Track’s length should be twice of door panel’s width (like your door width is 2FT, You will need 4FT hardware Kit). Single door= 2 X single door panel width (Like your door width is 3FT, you will need 6FT length kit). Double door= 4 X single door panel width (Like your door width is 3FT, you will need 12FT length kit).