All of our products comply with strict quality control and advanced technology makes CCJH Sliding Barn Door Hardware more reliable. Material: Carbon Steel Door weight capacity: 220lbs Sliding Length: 4ft-16ft for your choose The top of the Doors to the ceiling : Min distance is 6.7″ Suitable Door Panel Thickness: 1 1/4″ to 1 7/8 inch. 1Adjustable Roller hanger screws(from 3cm to 5cm), You can adjust the screw to the most suitable thickness for your door 2Rubber accessoriers & Spring door stops, has buffering effect when sliding door, reduce noise. Ackage includes: For Single Door. According to rail holes. 1 hole need 1 set. Roller Bolt: x4. Door Stopper: x2. T-shape Floor Guide: x1. Install Manual: x1. Ackage includes: For Double Door. Roller Bolt: x8. Door Stopper: x4. T-shape Floor Guide: x2. How to choose track length? Track’s length should be. Of door panel’s width (like your door width is 2.5FT/76cm, You will need 5FT/152cm Kit for single door). The length of the track should be four times the width of the door panel. (like your door width is 24”/61cm, You will need 96”/244cm hardware Kit).