Our double track bypass comes with dual tracks which allows each of the 2 doors to slide independently and perfectly stack behind one another. Made with carbon steel, this hardware kit can hold up to 220lbs. If all the bolts are secured into a stud or if a header board is used, the maximum weight capacity can reach 300lbs. The minimum clearance required from the top of the door to the ceiling is 8" for the hardware. The mounting holes are evenly spaced 16" apart to match regular stud placements. Tracks up to 7.5ft comes as a whole piece. Any lengths 8ft and over will come in two or more pieces joined together with a junction plate, thus the spacing between the two middle holes may not be 16". If the mounting holes do not line up with your studs, please use a header board.