Yes, the documentation does say so, it's why I bought this particular case. However, it's impossible to move them to that particular width because the holes to insert the rails into for 280mm are completely missing on one side of the case. So I have the rails inserted into the correct holes on one side and on the other side that it's missing I have it into the 240mm width holes which makes the radiator sit at an angle. And it prevents me from mounting a 140mm fan on the second set of rails since the radiator is going at an angle.