High-quality carbon steel maximum load 150kg:Barn door sliding kit are main made from carbon steel,except the wheels and the wheel bearings.Door kit roller material:PREMIUM NYLON.The wheel bearings are made of high quality STAINLESS STEEL.Rail track :carbon steel with powder coating to reduce the wear and tear, to keep a smooth and quiet movement in track.The sturdy sliding rail track kit can support up to 150kg. Specific size:Sliding door track for DOUBLE DOOR(the door panel is NOT included).Wheels diameter: 69.9mm. Sliding rail thickness: 5.8mm and width: 39.9mm. Fit for wood door panel width: maximum 457.5 mm and thickness: 35 mm-45 mm. Suitable for interior wooden doors:The sliding barn door hardware kit are design for interior doors,Some buyers also used on outdoors because they think the rusty barn door kit is more attractive Splicing sliding door rail：The length of the track is mostly spliced ​​by several sizes of tracks, which is convenient for transportation and also increases the firmness during installation. We promise：We are guarantee 5 years factory warranty. If you have any questions, please contact us FIRST, we will contact you within 8 hours,Solve the problem for you until you are satisfied., Weight: 10.361726314 pounds, Manufacturer: GIFSIN