CCJH 4FT/48''（122CM）Bi-Folding Barn Door Hardware Sliding Track kit Heavy Duty for 2 Doors, Carbon Steel[SUPERIOR QUALITY]: The bifold door hardware kit is made of high quality Carbon Steel with frosted black surface, rust resistance, durable, can maintain its beauty and longevity for many years. [TRACK SIZE CHOICE]: This 4FT 48"track, each door panel should be half the size of the door opening + 50mm 1. 97" and the track should be more than 150 mm 6" wider than the door opening. Suitable Door Thickness: 1. 18'' 1. 58'' [STABLE AND QUIET]: Carbon Steel