Customers can use thickness 45mm(1 3/4) door panel to reduce a little. Our suggestion is to make door panel more wider than openning(openning/2+4) to cover the sight between two door's gap. Track had been pre-drilled 16" apart holes, can be used for 16" apart studs wall. The bypass system need drill 3 line holes on the wall.It's very important to double check the level to make all of them in same height. Door panel need to pre-cut a groove(Width 3/5";Height 1") , pls let your door maker finish this job when you order the door. The item "6.6FT Brushed Nickel One piece Bypass Sliding Barn Door Hardware" is in sale since Friday, July 15, 2016. This item is in the category "Home & Garden\Home Improvement\Building & Hardware\Doors & Door Hardware\Other Door Hardware". The seller is "shengyinhardware" and is located in Carol Stream,IL. This item can be shipped to United States.