TSMST Bi-Folding Sliding Barn Door Hardware Kit, Right Choice for Your House. [DOOR PANEL IS NOT INCLUDED] How to Choose the Barn Door Track Length Recommendation track length > doorway width+150mm(6")Leave 150mm(6") from the upper edge of the door to the roof.Track length Fit door panel width36" track < 17"40" track < 19"42" track < 20"48" track < 23"52" track < 25"60" track < 29" Why Choose the BI-folding Barn Door Hardware Kit? The traditional parallel sliding barn door hardware can not meet the limited space of the door opening, the folding door kit solves this problem very well. Open the door without occupying wall space, suitable for placing furniture next to the door, and rationally allocate space. The pulley wheel is made of high quality nylon, which slides smoothly and quietly; It will not disturb you and your family to rest. The hanger and track is made of durable carbon steel, professional anti-corrosion operation; excellent finishaed surface, looks noble. The hanger roller and is consisted of upper and lower two parts, 360 degree rotatable. The folding door can be opened and closed freely and smoothly. What do I need to pay attention to when installing？ 1. The hanger should be installed along the edge of the door, the distance from the edge of the door to the screw of the hanger is 18mm = 11/16inch. 2. The installation position of the bottom rotating shaft must be perpendicular to the punching position of the fixed hanger, it means the distance from the center axis of the rotating shaft below to the door edge is also 18mm = 11/16inch. 3. Parcel contains 3pcs hinges for the combination of the 2 doors. To install the door and the hinges, both of them must remain vertical. 4. Parcel contains the detailed installation manul, please read carefully before installation. Note!!! 2 and 3 points must be paid attention to, both of the two situation may cause the door not to open.