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-20ft for your choose The top of the Doors to the ceiling : Small Wheel Min distance is 6.7″ Big Wheel 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. How to choose track size. 1 2 x Rollers 2 Wall Hanger Set (1 rail hole need 1 set) 3 2 x Door Stops 4 4 x Adjustable roller screws 5 2 x anti-jump blocks 6 1 x floor guide 7 Pre-Drilled Spliced rails Note: Only the sliding door kit for sale, door is not include. 1 4 x Rollers 2 Wall Hanger Set (1 rail hole need 1 set) 3 4 x Door Stops 4 8 x Adjustable roller screws 5 4 x anti-jump blocks 6 2 x floor guide 7 Pre-Drilled Spliced rails. Note: Only the sliding door kit for sale, door is not include. For Bypass 2 Door. 1 Pre-Drilled Spliced rails 2 4 x Rollers 3 Wall Hanger Set (1 rail hole need 1 set) 4 4 x Door Stops 5 8 x Adjustable roller screws 6 4 x anti-jump blocks 7 2 x floor guides. 8 Bypass brackets (1 rail hole need 1 set) Note: Only the sliding door kit for sale, door is not include. For Bypass 4 Door. 1 Pre-Drilled Spliced rails 2 8 x Rollers 3 Wall Hanger Set (1 rail hole need 1 set) 4 8 x Door Stops 5 16 x Adjustable roller screws 6 8 x anti-jump blocks 7 4 x floor guides.