WINSOON 16FT Bypass Barn Door Hardware 8 Rollers Kit System for 4 Wooden Doors (doors not include) Pre-purchase Information Doors are not included, only the hardware kit is for sale. You will need 9" clearance from the top of your door to the ceiling (or crown molding, if any) for this kit to fit correctly. Fit for door panel thickness: 1-3/8" to 1-3/4". This double track bypass hardware kit can hold 230lbs door both on the inside and outside track. The gap between door and wall is 5/8" and between door and door is 2" based on 1-1/2" thick door. Safety-ensuring Measures Support Bracket: It is made by solid 1/4" thick carbon steel, surper solid and steady. Flat Rail: Rail is made by solid 1/4" thick carbon steel coming with pre-drilled holes of 16 inch spacing, black surface finished. Hangers: The strap of the hanger is made by 1/4" thick carbon steel and the wheel is made by POM nylon, very durable, quiet and smooth. Rail Supporter: With lag bolts and the spacers, the rail can be securely attached to the studs and can hold 230lbs comfortably. Our bolts can be used to both wooden wall and concrete wall. Door Stops: You could install it to anywhere of the rail, and they're cushioned by rubber caps 4 Pair of L Floor Guides Two installation methods: Give you the option, allow you to not need to groove the door bottom. Perfect for any grooved or ungrooved doors, fit all thickness doors. The floor guide can prevent the doors from swing, allow you to open and close your door freely. Q: How do I know the length of track I need for my opening? A: Usually track length should be equal to your total two doors width or opening. For example, if you have two doors that are each 30'' wide. You will need 2x 30''= 60'' long track. Or if you have a opening that is 78'' wide, you will need at least 78'' long track. Q: Can I cut the rail to fit my wall? A: Yes, the rail can be cut to any length. We recommend using an angle grinder to cut the rail. Q: What is the weight capacity? A: Your door limited 230lbs. Q: What is the compatible door thickness? A: 1-3/8" ~ 1-3/4". Note: If you have door thickness that falls out of this range, please let us know your exact door thickness so that we can put shorter hex bolts for your thinner doors or longer hex bolts and spacer extenders for your thicker doors. Q: What is the minimum clearance required above door? A: At least 9". Q: When do I need a headboard?? a. If the pre-drilled holes in the rail don't line up with your wall studs. b. If there is a doorway trim. Attach a header board with the same thickness as your doorway trim into your studs first, and then mount the rail onto the header board.